Well, it only took two years, but the video follow-up to How to become the British Monarch is finally done and up. As usual you can read and participate in the official discussion thread on reddit.
Several experts helped fact-check this video, and I'd like to particularly mention Dr Carolyn Harris who helped add in some vital details and without whom the corrections section below would have been embarrassingly long.
Corrections:
The crown arrow from Henry VIII to Edward VI should be 1547 not 1509 the year of his father.
The official name is 'Wars of the Roses' not 'War of the Roses'.
Music by Kevin McLeod, not McLead.
Script:
1066! The start of the royal family on these fair isles. Well, there were kings and mini countries before that and druids before that, and Pangaea before that, but we have to start somewhere and a millennia ago is plenty far -- if that leaves out Æthelred the Unready, so it goes.
William the Conqueror, conquered in the 'Norman Conquest' -- Norman here being code for French.
Because it's the olden days, people had lots of kids, but to keep things simple this family tree is going to leave out many of them on each branch because not every child matters.
So William had three kids we care about: William II, Henry I and Adela.
If you've seen the video about royal succession -- click here if you haven't -- you'll know that formal rules for passing on the crown will get established, but for now, it's a free-for-all, home team advantage to the eldest son, but never forget bigger-army diplomacy.
Upon William the Conquerors death, William II became king.
William II didn't marry, and on a bros day out with Henry died in a 'Hunting Accident' that gave Henry I the crown.
Henry I had at least 26 children of which only two were 100% legit. He declared his daughter would rule next (after his son died in a ship wreck) and swore his knights to honor Empress Matilda by crossing their hearts, hoping to die, sticking a needle in their eye -- but when Henry I died while Matilda was in France, many ignored this while her cousin Stephen raced to Westminster using faster army diplomacy to get coronated first.
Empress Matilda did eventually return and start a decades-long civil war -- that was pretty much a stalemate because turtling in the 1100s was an effective RTS tactic.
While she did rule part of the island, as Matilda never had an official coronation, her monarchical status is disputed.
Now, as Stephen's children were either dead, disinterested, or a nun -- his crown went to his nephew, Henry II who had four sons: Henry the Young, Richard the Lionheart, King John… and Geoff. (Guess who died before his turn?)
Henry II saw the history thus far of conquering, assassination, (maybe) usurpation, attritional war -- and decided waiting until after the death of the current king before sorting out the next king didn't work.
So Henry II changed the system and crowned Henry the Young co-king with him, invoking the rule of two: one is none. Two is one. If it's important, you need a backup.
It was a good plan for stability, helped by the young King's popularity, but unfortunately -- the apprentice rebelled against the master, rallying his brothers -- which resulted in another civil war of disputed monarchs during which Henry the Young died of dysentery, Henry the Elder died of fever, and Richard I took the crown.
After Richard came John and four eldest son successions in a row: John to Henry III (insert Magna Carta here) to Edward I (Longshanks) to Edward II -- to Edward III.
Actually Ed II was overthrown by Isabelle of France A.K.A the She-Wolf of France A.K.A. his wife. After deposing her husband, she acted as regent for their son. Every one of these arrows glosses over a bit of complexity.
Edward III had five sons: Edward the Black Prince, Lionel, John, Edmund, and Thomas, none of which would wear the crown.
When Edward III died, his throne would have gone to The Black Prince, but he was dead at the time so the crown went to his boringly named son Richard, now the second.
There's a bunch of drama lamma stuff around Richard the second which your English teacher might force you to read about -- but spoiler alert, history's ending is always the same: bigger-army diplomacy, this time from Henry IV who gets the crown and Richard II gets starvation in captivity.
Another Henry before we get to the War of the Roses:
A war that strikes terror (and boredom) in the minds of students of history the nation over who have to deal with this family tree 'simplified' to explain why everyone was angry, but the shortest version ever is Edward III's great, great, grandsons duked it out, even though one of them was dead for part of the fight -- but we can't get into that now so Henry VI to Edward IV to Henry VI to Edward IV. The end.
Edward IV, on his deathbed left his crown to his son. But being twelve he needed protection, so Richard, his best-ist uncle in the world, promised to take super-good care of him. Edward V then promptly disappeared under suspicious circumstances that left Richard to become Richard the third.
But he didn't stay king for long because Edward III's great, great, great, great grandson Henry VII -- took the crown, put a ring on Elizabeth of York to lock down that royal legitimacy and then sired Henry VIII -- splitter of churches, and ladies.
Henry VIII thought it was high time to formalize the rules of inheritance, so he wrote them out in his will -- basically saying oldest boys first, girls only if there aren't any boys -- and Parliament approved the rules.
Which should have made everything neat and tidy, but we're about to enter the really messy time...
… Because Henry's son lived just long enough to screw it up -- inheriting the throne at 9 there was, of course, a scheming protectorate running things, yet he still declared at 15 that his father's rules were dumb and his sisters were dumb and that his first cousin once removed, Lady Jane Grey, should be the next monarch instead.
Then he died and Lady Jane Grey became queen at sweet sixteen, sort of -- in a disputed status way for nine days, until beheaded by Mary, the first really, truly officially nobody doubts it Queen.
Mary didn't have any kids, and passed the crown to Elizabeth I who became the second queen in a row… to also not have children. But, no problem because Lady Jane Grey was next in … oh. Right.
Now, this is the point at which we acknowledge, Scotland Exists. They'd been doing their own royal thing which for our purposes joins the English branch where Edward III's great granddaughter married into it in the 1400s and then goes: James, James, James, James, James, Mary Queen of Scotts, James. Bringing us back to the 1600s.
Henry the VIII's sister importantly also married into this line of the family giving it English legitimacy points in the eyes of the English Parliament, which asked to borrow Scotland's James, making him king of two countries with two numbers in his name depending on where you're counting from.
James had a son, Charles I, and you might think this unification of the monarchs means the very messy time is over.
But no.
Because Cromwell.
Cromwell didn't like kings and beheaded Charles I: declaring no royals no longer, making himself The Lord Protector which was in no way like a king -- even though he was in charge and it was a hereditary office passed to his son.
But the Cromwells didn't last -- mainly because his son was a fancy country squire who didn't follow rule 0: keep the army happy -- giving Charles's son, Charles II, the ability to reestablish the monarchy.
Charles II had lots of children, all of which were illegitimate, leaving his brother, James II next in line. But James II was Catholic and ever since Henry split the church, Catholics had terrible approval ratings. But conveniently, he had nice Protestant daughters, one married to a Dutch Prince who by the nature of these things was the grandson of Charles I. Bonus English legitimacy points, plus, who doesn't like the Dutch?
With James so unpopular and William and Mary so popular, the army and nobles pretty much invited the royal couple to 'invade' and James II fled.
William and Mary ruled as co-monarchs, but without children the crown went to Queen Anne, who also didn't produce any heirs, though not from lack of effort -- she was pregnant seventeen times.
Again, finding themselves with a no-royals-no-longer situation, Parliament decided it was really, truly seriously the time to sort out the rules of inheritance to avoid pretenders from every branch of this messy tree fighting over the crown.
Parliament did a royal reboot to clear the cruft, defining Sophia of Hanover -- the granddaughter of James dual numbers to be the new starting point for all claims to the crown.
These rules finally stuck, thus ending the very messy time.
George I, son of Sophia, was the first king under the new rules, then his son George II, to George III, and even though he lost America and his mind, never fear, the rules are here, so the crown continued to calmly descend the family tree, going to George IV, who didn't have any surviving children, to William IV who had ten children -- all illegitimate, then passing through his dead younger brother to Queen Victoria who started her reign in 1837 and made it to just over the finishing line of the 20th century. Which is a doubly impressively long time given the state of medical technology then. After the end of her age, the crown went to her son Edward VII to George V…
to Edward VIII who finally breaks up this neat and tidy (and somewhat boring) line of succession by committing a scandal: marrying a commoner. An American Commoner! An American Commoner divorcee! twice over
::Gasp::
Actually, the divorces were a real problem and weren't compatible with the Monarch's role as Head of State and also the Church of England in the 1930s. Edward abdicated to his brother George VI -- who was reluctant to take the crown, and then had to oversee World War II and the subsequent breakup of the British Empire -- which drained the reluctant King's health, who died at 56 leaving the crown to Elizabeth the Second, in 1952 at the age of 25. Seven years older than Victoria, her great great grandmother was on her coronation day, but in early September, 2015, Elizabeth became the longest-reigning Queen in not just British history, but world history.
From Elizabeth II the crown continues on to Charles, the longest heir apparent in British history, to his son William, to his son George.
And that, is a brief history of the royal family.