A Tale of a Lost Heir
Lost or dispossessed heirs are frequent protagonists as they try to win back their rightful crowns. But the story also actually happened in history.
Lost heirs to kingdoms - or dispossessed heirs, for a more precise term - are frequent protagonists in novels, as they try to win back their rightful crowns. The premise dates back at least to Greek myth, and continues strong down to the present day. But, winning a crown is a hard business - not only hard to do, but also hard to plot out and write about, especially when you've only got other novels to go off.
But, this storyline did happen in real history - and writers can use that for advice. I was recently reading about one such case: "Bonnie Prince Charlie" in the '45, as the 1745 Jacobite uprising is called.
Prince Charlie was the grandson of King James II of Scotland and England, who got overthrown in the Glorious Revolution. To try to get his father back on the throne, he landed in Scotland, raised an army from next-to-nothing, conquered much of Scotland, and got more than halfway to London before turning back and being defeated.
I've got many opinions on this, especially since I enthusiastically approve of the Glorious Revolution, and he was trying to reverse it. But while I was reading the book, what was most in my mind was how this can be an example for how to tell the story of the lost heir well.
The first question is, why are people following your lost heir? Why are they supporting him in his quest to take back the crown?
Bonnie Prince Charlie had great charisma. He landed in the Scottish Highlands with one small ship, talked some local clan chiefs into following him, and then snowballed from there until he had enough of an army to defeat the armies sent to stop him. Then, he kept inspiring his soldiers, by success and by charismatic conversations and speeches and by being happy to take on every exertion he asked of them. He's one of the people who seem exactly suited for exactly one time in history.
(Also, the existing government of King George II was rather unpopular.)
The best writers learn from this to have their heirs be the sort of people whom people obviously want to follow. Tolkien does this with Aragorn. Frances Hodgeson Burnett in his Lost Prince goes a different tack with his young Marco - he's not an inspiring leader as such, but he's an inspiring example with his charity and self-denial and great dedication to the cause.
C. S. Lewis avoids this in his Prince Caspian, but he realistically shows it as a weakness. His (very young) Caspian shows no great virtues except friendliness when he first meets the "Old Narnians." They lend him their support largely because some of them believe a human king is important, and he's the only friendly human available. But, this doesn't explain why anyone would actually follow him himself... and indeed, we see his cause almost breaking up from quarreling before the much more charismatic Pevensies arrive. Lewis realistically shows that few people were ready to follow Caspian, because they didn't have strong reasons.
The second question is, why is your lost heir able to get a substantial power base without being immediately swamped by his enemies?
Northern Scotland, where Bonnie Prince Charlie started, was so extremely remote it was almost impossible for an army to get there to fight him. What's more, Britain was in the middle of the War of the Austrian Succession, with its army on the continent; it took time to gather an army - time delayed even more by political infighting and incompetent politically-appointed generals. Between talent and luck, Prince Charlie had picked exactly the right place and time to strike. If King George had been overthrown, historians would have had a rich tapestry of faults to point to.
Lewis explains this with one of these reasons: the Telmarines largely ignore the remote forests where Caspian and the "Old Narnians" are gathering their forces. Burnett picks something similar to another reason: two other factions in Samavia are fighting each other, so neither is able to suppress our lost heir's supporters. Any number of reasons will serve, as long as one makes sense - it might seem improbably convenient, but that's the case in real history too!
Or, an author can sidestep the issue, like Tolkien did: Aragorn resolutely refuses to oppose the Steward of Gondor until the Steward dies and his people invite him to be king. This only works because the story is largely about the struggle against Sauron, where Aragorn is able to win support without assembling any intentional powerbase.
The third question is, if it does come to war, why doesn't the lost prince get defeated when he's fighting against the established government with all their resources?
At the start, King George's government sent out incompetent captains against Prince Charlie, with few troops. It's no wonder he defeated them. But it's implausible for that to keep happening - and, indeed, it didn't. By the time he was at Derby deciding whether to descend on London, the Duke of Cumberland - a competent leader - was already in the field.
Prince Charlie's other stratagem was speed. He simply outpaced many of his enemies. Militarily, that meant he didn't risk fighting them - but psychologically, it meant he was seen to go from success to quick success. That kept his army together; that encouraged his allies more than any battlefield victory. But when he finally retreated rather than descending on London, his army quickly fell apart even before Cumberland attacked.
Most writers of lost-heir novels leave this largely offstage, not ready to write about military tactics. Tolkien's Aragorn refuses to fight against Denethor; the battles in Burnett's Samavia are all offstage. Lewis does bring it onstage... but his battle is won by the terror of the Dryads, and then a miracle of Aslan.
The fourth question is, how will your lost heir govern?
Prince Charlie largely didn't have the opportunity, because he didn't hold much territory. Most of the cities he'd captured were lost once he and his army moved further south. On top of that, he was (sensibly enough) spending almost all his time with the army until he was finally defeated.
The fictional examples I've cited win, and we do get at least a sketched outline of how they virtuously reign after. That isn't the focus of the story, but we see at least a bit of it. And, we see how they've displayed virtues throughout the story that will serve them well on the throne.
Prince Charlie was (of course) defeated, so we don't see that. Instead, we see him fall into despair and drink at seeing his cause lost. I could optimistically guess that victory, and a life as King of England rather than a washed-up might-have-been, would give him enough spark to avoid aimless drunkenness - it's not sure, but very possible. At the least, it would give him more responsibilities, especially if his father abdicates in his favor like he planned.
There's very little telling how a Jacobite-ruled Britain could go. Prince Charlie said he planned to leave the British government largely alone aside from undoing the Act of Union between England and Scotland, but his return to the throne would inherently reverse at least part of the Glorious Revolution. Would the Bill of Rights also eventually be nullified? The ideas of a Bill of Rights and Parliamentary supremacy? Any of this could have momentous consequences for the future - in England and America and around the world.
Long-term consequences like that, of course, are outside the scope of a fictional story. An author probably wants to end their story with something that looks like a happy ending, but there's a lot of leeway in framing that.
More important than that, though, is making the plot feel plausible. It's a hard job taking the crown, and it should feel hard to the reader. A protagonist should always struggle in the plot of their story, but taking a crown should be an even harder struggle than most. All the four questions I've called out should feel hard inside the story - but they should be set up so the protagonist can indeed meet them in a way that feels plausible to the readers.
And one good way to make that feel plausible is to follow the lead of actual history. History sometimes looks implausible - but it lets you look into how things worked and pull out ideas from beyond your imagination.