Here's an actual example from HttT
He's had a longer and more active reign than most, but that just makes it easier to show the quirks. It's a great idea, but it's probably better to keep it really simple rather than rely on the computer to string everything together.
I agree and disagree, I agree that it should be kept simple, yet I disagree that it shouldn't be stringed together. What needs to be recorded are things that are not spammed for the most part, such as your festival example.
Charles of Lancaster was born in 1102 to Duke Jon of Lancaster and the Duchess Mary of Lancaster. He had a passion for the arts, was religiously faithful, and was considered a brilliant tactician. He inherited his father's drinking problem and was known to be a raving drunk. He became King Charles IV of England in 1118 by inheritance. He participated in the bold English-French War of Conquest in the year 1120 where he lead an army of 2,000 men against an army of 10,000 men in the Battle of Agincourt, which he emerged triumphant. Charles participated in the Crusade for Jerusalem, which was initiated by Pope Leo IX in 1121. He participated in the disastrous Battle of Antioch in the year 1123 where he was defeated. Charles of Lancaster succumbed to his wounds in the Battle of Antioch and died in 1123. During his lifetime he saw the provinces of Agincourt, Crécy and Poitiers gained. People remember him by the name, King Charles the Bold.
The first part of my example isn't spammed, it's his name, when he was born, and who he was born to.
Second is the 'ending' traits that he had, and those were put into sentence form, so this wouldn't be spammed either.
The third part is a necessity, although it could be spammed, but the spamming of wars isn't a bad thing, they provide different information depending on who your fighting, your troop amounts, and if you were successful or not.
The fourth part is the Crusades, and if it's like anything in the original CK, they are not spammed much, they just last a long time.
The fifth part is the provinces he conquered, and yes you could potentially rack up a large list if a person plays like a warmonger, but I don't view that as bad. To cut down on the list, it could default to the larger size, for example if you capture a bunch of counties it will list the counties, but if you capture entire duchies instead, it will just list the duchies instead of the individual counties in that area.
The sixth part is how he died.
The seventh part is just the name he was remembered by, which could be incorporated into the first part, but for my example I tossed it on the end.
The only parts in there that could be somewhat heavy on spam is if you are a warmonger, and capture tons of provinces (which could be condensed in name - aka duchies), and the battles fought. If they incorporate national decisions in the form of royal edicts (not sure, just guessing) that wouldn't be spammed either (ie, Henry IV wisely enacts 'Divine Supremacy'), since you wouldn't be flipping back and forth on those.