The longest family tree I've made so far (309 years of the House of Montgomery (41 BF- 268 AF))
CONTEXT: Ok so this is some extended (aka barely mentioned) lore for my webseries, They Who Hide Under Top Hats.
Quick Rundown:
Grand-Prince (or GP) of Hatlynshire, St Jacob Brackenburg (not listed here) adopts George Montgomery, a boy who was orphaned after his home was burned by the Woodland Folk (WF) - basically magic wizard people who live in an eldritch forest- in their forever war against the People of Hatlynshire. After Jacob dies St George takes over as GP and, alongside his wife St Amia and his own adopted daughter St Annalise of the Burning Banner ends the forever at the Battle of the Field of the Triumph, allegedly driving the WF into extinction and ending the BF (Before Field) era and starting the AF (After Field) era.
Once George dies his son Thomas takes over, during that time Hatlynshire (since the war is over) begins to industrialize and bunch of oligarchical anti-monarchist anti-establishment capitalists start autonomous states called the Outer Boroughs, forming the New Industrialist Movement (NIM).
Thomas dies, his son Claude takes over, the NIM gets stronger and starts really opposing the Hatlynshire Government, Claude (being under a lot of stress) then gets depressed, falls to alcoholism and offs himself in 56 AF. Since his son Carlton is an infant, his wife Alissa rules as regent, except it goes so bad that the government (which is controlled mostly by the old nobility like the Del Suttons, the De Vicis, the Millfields, etc) ousts her after 11 years and says "Screw male primogeniture" and installs her older daughter Victoria as GP. Victoria democratizes parts of the government that keep the old nobility in power, makes a bunch of state corporations to challenge the NIM, murders the unofficial head of the NIM (Corsman Gaft) and eventually goes to full on war with the NIM during the War of the Coin and wins, causing the NIM to collapse in around 89 AF. Along the way she meets and official named Bernard Sorah (who becomes like the second most powerful person in the world) and they have an illegitimate daughter named Olivia.
Victoria loses popularity by the end of the century and is dethroned in a coup by her brother Carlton in the New Century Conspiracy around 100 AF, she and Sorah go into hiding but luckily Carlton is a horrible ruler and is also dethroned by a counter-coup 5 years later, letting Victoria return to power, she then rules until her death in 135 AF. Carlton's former supporters (being sore losers) reject the monarchy entirely and become the pro-democracy Liberationists.
She is replaced by her twin nephews William and Wyatt (who like her more than they like their dad) and they preside over the War of the Banners which reveals that SURPRISE the Woodland Folk are NOT dead, just hiding amongst the humans. Once the War is over they decide that the WF are actually dead this time (they're not). They also deal with the Liberationists, who combined with the leftover Industrialists from the former NIM have once again come to challenge the Monarchists. Hatlynshire comes to the edge of civil war until they come to the Compromise of Coin and Crown where the GP agrees to be a figurehead while the new head becomes the elected Mayor of Hatlynshire. However, in the first election the winner ends up being Olivia Sorah (Victoria's illegitimate daughter and prominent politician) and with her the twins form the Order of Man, which is a shadow government that allows the GP to be a secret dictator.
Once the twins die their kids (the Line of Wyatt and the Line of William) do a whole family feud where they murder each other over who gets the crown with Olivia's own illegitimate son, Maxwell Gaft (great grandson of the assassinated head of the NIM Corsman Gaft) joining in too cause he was RICH af (basically if J.P Morgan had J.D Rockfeller type wealth). His daughter Florence marries Chester Wurths, son of Princess Wilhemina, joining the illegitimate line of Olivia Sorah with the Montgomery line again.
Anyways the Montgomery Feud with Victoria Elsabeth Montgomery (daughter of the murdered Wilsom Montgomery) being GP, she builds a bunch of stuff and completes a lot of projects before dying and passing the Crown to Thomas II in 220 AF (skipping Mary Annalise since she had kids). He rules for five years before dying and giving the crown to Joseph Wilson Montgomery, cementing the Line of Wyatt as the true line of the Royal House.
Meanwhile Florence and Chester get murdered by Prince Fredrick William cause he blamed Maxwell Gaft and Wilhemina for the Line of William losing the feud. Luckily he is then killed by the Christopher and Emma Wurths-Gaft in his own palace with the help of Fredrick's illegitimate daughter, Sophia Pearlborough, forever ending the infighting within the royal family for now.
Ngl there is so much i didn't get into like the details about how Maxwell's business empire was built and undone by the govt, how the Liberationists and the Monarchists descended into mob violence prior to the Compromise which coincided with a fued between Olivia and her second cousin Margaret Cristenwall. Not to mention that, while this tree end at the end 268 AF...my actual story takes place in the year 634 AF which means i have SO MUCH more lore to make up.
But yea if yall wanna hear more about a particular part of the history or the family tree, feel free to ask questions! Thanks for listening to me yap! :D