Here are ten tests to check if your alternate history is plausible.
Summary
First, a plausible AH can include major changes caused by the
actions of a person of improbable origin, e.g. Napoleon, if
it shows that socio-political and technological circumstances
were such that such a person could make the changes
A plausible AH extending more than a few years beyond the point
of departure should, like real history, include some unexpected
world-altering individuals, and develop the socio-political
environment that enables their actions to be believable.
Click here to read more on world-altering individuals.
Second, a plausible AH would capture the socio-political and
technological evolution of the era.
Click here to read more on socio-political and technological evolution.
Third, a plausible AH does not go to extremes that contradict
the socio-political and technological realities of the era. For
example, it does not create an empire that lasts too long, or a
people rising from the ashes of defeat to dominate the world.
Click here to read more on socio-political and technological realities.
Fourth, a plausible AH does not use a dramatic event, in isolation
from socio-political and technological changes, as the means of
creating major changes.
Click here to read more on an event isolated from socio-political and
technological changes.
Fifth, a plausible AH does not fall into the "enduring empire"
trap.
Click here to read more on the "enduring empire" trap.
Sixth, a plausible AH does not fall into the "super superior
empire" trap.
Click here to read more on the "super superior empire" trap.
Seventh, a plausible AH does not fall into the "easy erase"
trap of removing something from real history that was the natural result
of socio-political and technological developments. For example having
an empire collapse without apparent reason or not forming, despite
the presence of factors that make this by far the easiest course
of action for people to take.
Click here to read more on the "easy erase" trap.
Eighth, a plausible AH does not make technology appear suddenly and
achieve wide adoption without preparing the socio-political context.
Click here to read more on sudden technology.
Ninth, a plausible AH covering more than a few years after the
point of departure will show the progressive accumulation of
changes in peoples beliefs, in their socio-political and economic
activities, and in their technology.
Click here to read more on accumulated changes.
Tenth, a plausible AH will eliminate all historical personalities when describing events many years after the change. It does not use contemporary real world people unless their birth antedates the point of departure, or the date on which the effects of that change impact on their parents or ancestors.
The larger the change resulting from the point of departure and the further back in history it happens, the more likely that individuals will be different from their contemporaries in real history.
This might be visualized as a "ripple effect" of accumulated micro changes.
Micro changes propagate when people are influenced by the effects of the change resulting from the point of departure. Microchanges will propagate much more slowly where local cultures are mainly isolated from the outside, as was usually the case before the 19th century.
The consequences of the microchange effect are strongest in eras when the composition of the elite population has direct consequences on politics. History is full of wars caused by dynastic disputes, and elites elbowing for more power. These events are most sensitive to microchange effects.
This microeffect on dynastic wars was at its peak in Latin Christiandom when wars were fought to support claims to dynastic titles. After the 16th century there was a shift to sovereignty based on support of the population, and wars became more closely related to national interests.
But even at their peak, most dynastic wars did not affect the net result of the vast number of small contradictory events that are summarized as economic and social history.
Finally, it is unclear how fast it is plausible for micro changes to propagate. I suspect that the effects of specific historical changes on alternate histories would be closer to the insensitive than sensitive model. In other words, forget the "butterfly effect" if you want plausible alternate history.
Click here to read more on how historical personalites are cut by micro changes.
Discussion
A plausible AH can include major changes caused by the actions of a person of improbable origin, e.g. Napoleon, if it shows that sociopolitical and technological circumstances were such that such a person could make the changes.
Consider the Napoleon of real history. France acquired Corsica in 1768, just one year before he was born there as Napoleone Buonaparte, which enabled him to attend military schools in France, enter the French army, and perform the extraordinary actions that extended French influence throughout Europe. If France had not acquired Corsica at that time he would not have the scope to fully demonstrate his genius as conqueror, military tactician, civil administrator, and governmental and judical reformer.
But, with the exception of his improbable origin, the Napoleon of real history would be plausible if he was a created as an imaginary character in an AH because the chaos of the French Revolution gave him the opportunity to acquire power. The Levee en Masse established by the revolutionary government and its wars with the monarchies, gave Napoleon the tools to exercise his skills as military tactician and conqueror. The revolutionary destruction of the autocratic system gave him the opportunity to place his imprint on the efforts to devise a new legal system, the Code Naploleon, based on the old Roman Corpus Civilis. But his spectacular military victories and extensive conquests provoked the monarchical powers outside his empire, Britain and Russia, to ally and finally defeat him. His conquests implanted French revolutionary ideas, and the Code Napoleon as model legal systerm, in most European countries. The entire sequence is plausible.
Napoleon is far from the only improbable individual in real history who has had a huge impact on history. For example the history of the Roman and Persian empires up to the 7th century gave no hint that Muhammed would receive God's message and that it would be adopted as a battle ethos by Arabs at the very time when the two great empires were exhausted by devastating war.
Other examples include the appearance of Joan of Arc at just the right moment for the French to chrystalize their national identity in the 100 years war with England, and Adolph Hitler at just the right moment for Germany to transform into a "blut und volk" neo-medieval totalitarianism.
A plausible AH can use the acts of an individual to produce explosive changes, but it must time these acts to fit the sociopolitical realities of the era.
A plausible AH extending more than a few years beyond the point of departure should, like real history, include some unexpected world-altering individuals, and develop the sociopolitical environment that enables their actions to be believable.
2. Socio-political and technological evolution
A plausible AH would capture the sociopolitical and technological evolution of the era. I would implausible to invent a Napoleon type figure that operated as if there was no such evolution. Such a figure would be as unbelievable as if, instead of Napoleon, the writer described Louis XVI, or a royal successor, as becoming a Napleonic style Emperor based on the French monarchy, who conquers Europe without the context of revolutionary popular enthusiasm and changes such as the Levee en Masse.
3. Socio-political and technological realities
A plausible AH does not go to extremes that contradict the sociopolitical and technological realities of the era. For example, it does not create an empire that lasts too long, a people rising from the ashes of defeat to dominate the world, or sudden appearance of anachronistic technology.
Some implausible Napoleon AH's that fall into these traps are:
Napoleon conquers the world, and his world Empire thrives until
the present;
Napoleon's defeat inspires France to become the leading world
power, and the world adopts French as the world language, and
Napoleon encourages technological progress which fills the
skies with airships by the 1880's.
4. Event isolated from socio-political and technological changes
A plausible AH does not use a dramatic event, in isolation from sociopolitical and technological changes, as the means of creating major changes.
For example, the Napoleonic era was much more than the story of Napoleon. It was the synergy of Napoleon with a complex and evolving set of revolutionary changes.
A plausible AH does not fall into the "enduring empire" trap.
Your AH is very unrealistic if it uses great empires lasting for very long periods of time. The favorites for this trap seem to be Rome, Byzantium, Napoleonic France, and the British Empire. The only empire to endure for thousands of years was imperial China, and it did not endure as a unified state for more than a few hundred years at a time. Rather, its unity was interrupted by long periods of breakdown and partition. A plausible AH could apply this pattern to Rome, for example, but it would have to change Rome's sociopolitical character to incorporate features equivalent to those of Chinese society that enabled the state to recreate itself after each collapse.
Also, just because an AH empire looks good on the map, doesn't mean that it is plausible. It needs to be based on the same factors that made it possible for empires to exist in real history.
6. "Super superior empire" trap
A plausible AH does not fall into the "super superior empire" trap.
It's extremely unrealistic to create an empire by starting from a single change and force subsequent events into a chain leading to huge present day civilization that dominates the world affairs to an extent unmatched in the long term by any power real history.
Some of the worst AH's are those in which the world is dominated by one or more great powers or ideologies. For example, Hitler wins WW II, and a Nazi super Reich dominates the present world. One of the few AH's to handle this in a remotely plausible way is P.K.Dick's The Man in the High Castle. Much of the plausibility comes from the fact that the AH is situated just a few years after the war.
The most famous example of a super empire is the fictional "Draka." But this might be excused by noting that the Draka are not a human society. So they can have far-sighted and forward-looking leaders who are super-human, who pursue perfectly achievable goals, and are never distracted by political pressure or sentiment. The inhuman Draka are a perfectly united society with agreed goals, whose only human characteristic is the occasional questioning of the means.
A human empire based on these criteria would be sheer fantasy.
Rather, a plausible AH empire would exist in a world which, though different than our own, places constraints on the scope and duration of the empire's power.
A rare example of a plausible AH empire is Fatherland, a novel that describes a range of people in a German society over twenty years after the war, and suggests that the Greater Reich did not achieve more world power than the Soviets did in real history, and that the Reich is reaching the end of its "term of power" as, for example, the SS has declined from its WW II fanaticism into a Mitteleuropean style police bureaucracy interested mainly in showing a satisfactory record in clearing criminal cases, and long suppressed scandals are being unearthed.
A plausible AH does not fall into the "easy erase" trap of removing something from real history that was the natural result of sociopolitical and technological developments. For example having an empire collapse with out apparent reason or not forming, despite the presence of factors that make this by far the easiest course of action for people to take. Examples range from the USA/British Empire/Roman Empire/China breaks up in [pick any year], to the USA/China/[other country/empire] never unites. For the erasure to be plausible, an AH needs to give a thorough explanation of how sociopolitical and technological circumstances would differ from real history.
A plausible AH does not make technology appear suddenly and achieve wide adoption without preparing the sociopolitical context. The classic example of this trap is the Roman steam engine. To make one you need to develop a lot of antecedent technology. This ranges from iron boring tools (developed in real history to make more accurate boreholes in cannon), to pressure measuring and control guages (developed in real history as scientific devices). Plus, you need to change the sociopolitical realities of the Roman Empire. Labor was cheap. There was no market for a labor saving device like a steam engine.
A plausible AH covering more than a few years after the point of departure will show the progressive accumulation of changes in peoples beliefs, in their sociopolitical and economic activities, and in their technology. The AH should include predictable population changes per growth rates and occasional setbacks from disease and war, independent invention of various technologies as the prerequistite tools and markets evolve, repeating waves of changes in prices (periods of inflation, followed by disorder, followed by price stability), and social consequences of new technologies, such as the questioning of authority that resulted in real history from widely dispersed printing presses liberating the diffusion of ideas from control by church scriptoria.
10. Historical personalites cut by micro changes
A plausible AH will eliminate all historical personalities when describing events many years after the change. It does not use contemporary real world people unless their birth antedates the point of departure, or the date on which the effects of that change impact on their parents or ancestors.
It is not only implausible, but logically impossible to have Richard Nixon selling steam cars in a world over 200 years after the US did not have a Revolutionary War. This was actually used, in The Two Georges, where it seems to have been intended as a satirical element. Use this device only if your interest is in entertainment to the exclusion of plausibility.
The larger the change resulting from the point of departure and the further back in history it happens, the more likely that people in this AH will be different from their contemporaries in real history.
This might be visualized as a "ripple effect" of accumulated micro changes.
Microchanges propagate when people are influenced by the effects of the change resulting from the point of departure.
For example, pick a point of departure 25 years ago, e.g. no Watergate.
Historical changes in this AH are going to result in a lot of different people being born.
We could go so far as to argue that even if there is a minute change in peoples' behavior as a result of a change in history, a different sperm would fertilize the egg and a different individual would be born.
But lets consider the effects of a single secondary change.
Henry Smith and Susan Smith are happily married in the 1970's and are trying to have children. In real history Henry (not a sports fan) was interested in following Watergate developments and watched a lot of TV coverage. They finally had a child, Jenny Smith, in April, 1975. In this AH, there is less TV of interest to Henry and he spends more time with Susan. They have their child, Bob Smith, December, 1974.
The macro history in which Bob Smith grows up differs from that of Susan Smith. The US suffers in the 1970's from post Vietnam syndrome, but not from the loss of trust resulting from Watergate. There is no Carter presidency. Instead the US elects a Republican successor to Nixon in 1976, a young fellow who we will call President Teflonio. Like Reagan he is inspired by free market ideas but has a long way to go before he can convince congress to begin cutting the welfare state. The Soviets don't gamble, unlike real history, on the Afganistan intervention. Ayatollah Khomeni revolutionizes Iran but there is no prolonged hostage crisis. Teflonio pulls out all American embassy staff at the first sign of trouble. But this AH resembles real history in that the US outspends the decrepit Soviets under their Chairman, lets call him Kissoff, and the Soviet Union implodes in 1985, earlier than in real history. But Kissoff, unlike Gorbachov, manages to keep Belarus in the Russian state. There are some noticable differences because in the 25 years since the no-Watergate point of departure there has been a gradual shift to a different population of elite individuals. Some of these have have strong and original personalities and agendas. President Teflonio was a big Star Treck fan who managed to persuade congress and the public to fund a space program with 50 times the funding in real history. This AH can expect humans to arrive on Mars by 2010.
But neither Bob nor Susan have any specific impact on history by 1997, nor for that matter will their descendants. The inflation rate is be about the same, the Arabs kill Israelis and vice versa, jobs are becoming more and more specialized, the welfare state is being recognized as too expensive to maintain in its present form and governments have become deficit fighters. Most people in this AH, as in real history, just go about their lives as big event takers rather than big event event makers.
By 1997 the US population consists of people born before watergate, who are the same as in real history, and many other people born in the 25 years after Watergate who are the same because their parents never noticed Watergate or were affected by it in any way before they were conceived. But a large proportion of the US under 25 population consists of different individuals than in real history. In other counties the Watergate effect lessens in relation to the cultural distance from the US. But the secondary effects of no-Watergate, such as the absence of a Soviet Afganistan war in the late 1970's, are having increasing effects on the composition of the population, such as the completely different offspring of soviet soldiers who were not sent to Afganistan.
Microchanges will propagate much more slowly where local cultures are mainly isolated from the outside, as was usually the case before the 19th century. For example, the microchanges resulting from a Vinland colony that survives in an AH and Europe before the 14th century, when communication ceases between Vinland and Scandinavia, would have limited effects in changing who was born in southern Europe for the next few hundred years, because of the small number of people involved in the relations between Vinland and Scandinavia, and the limited relations between Scandianavians and people elsewhre in Europe.
It is plausible, for example, to write this AH so that the microeffect ripples do not reach so far as to eliminate Portugal's Henry the Navigator. Henry could well exist and, having only garbled reports about the Vinland colony, which he could interpret as being some sort of Arctic extension of Scandianavia, would see it as having little to do with the Portugese quest on the coast of Africa and the developing search for India and Prester John's Kingdom via circum-Africa ocean voyages using the new ship design produced by the work of many researchers.
The consequences of the microchange effect are strongest in eras when the composition of the elite population has direct consequences on politics. History is full of wars caused by dynastic disputes, and elites elbowing for more power. These events are most sensitive to microchange effects.
The most extreme result of the microchange effect on indivduals can be seen in the improbable rise of the Hapsburgs in real history. They acquired of the Netherlands because Burgundian duke Charles the Bold died childless. A few years later they also acquired Spain when after the death of the Spanish monarchs, Ferdinand and Isabella, who had a son who did not live. As a result of the Spanish acquisition, Charles V Hapsburg, gained access to Peruvian silver to fund his opposition to the Protestant Reformation. In exchange Spain received the Trojan horse of owning the Netherlands, which dragged Spain into a century of heavy expense and frustration in a futile war to hold and re-Catholicize the Netherlands.
This microeffect on dynastic wars was at its peak in Latin Christiandom when wars were fought to support claims to dynastic titles. After the 16th century there was a shift to sovereignty based on support of the population, and wars became more closely related to national interests.
But even at their peak, most dynastic wars did not affect the net result of the vast number of small contradictory events that are summarized as economic and social history. Whether or not the Hapsburgs acquired dynastic dominion over the Netherlands, they would have modernized while Spain lagged. The waves of economic inflation, crisis and price stability would have continued. The conflict between the national interests of France and Spain would have continued.
The main difference between real history, and an AH where the Hapsburgs did not acquire dynastic control over the Netherlands, would be the names of the elite players and the specific games they played, wars they fought and bastards they fathered.
Finally, it is unclear how fast it is plausible for micro changes to propagate. At one extreme one could argue for the "butterfly effect" where even a butterfly flapping its wings has a ripple effect, with major changes in weather. But this is too simple. Chaotic systems theory accepts this as a possibility known as "sensitive dependence on initial conditions." But is just as probable that even a major event, such as a nuclear explosion in the atmosphere will not affect global weather. This is known as "insensitive dependence on initial conditions."
I suspect that the effects of specific historical changes on alternate histories would be closer to the insensitive than sensitive model. In other words, forget the "butterfly effect" if you want plausible alternate history.