misunderstood legacy ?

[ASIOOOX]

hi guys i started in 1066 with the little king from Ireland, got some territories and children but i thought that the son who had to receive the heritage was the 'heritage son' like it s written (i have my game in french so he s called 'héritier', my translation may not be accurate) but when i died my son just got ONE territory, not all my titles, i gave my HEART to that 'intro game' i got beaten up by the england king in my 4th year of reign... anyway, i m not dead yet in another game with the same character, can someone help me to keep my titles ? do i have to put all (except one) of my children in the jail and wait them to die ?

[Deusmodeus]

You likely have partition.
conqueror more land and it give to the other sons.

[AC Denton]

This is the gameplay loop of Crusader Kings: managing who inherits what and trying to keep everything together.

When you die, your succession law determines who gets what. Your succession screen will give you all this info, detailing exactly which titles each person will get.
The strategy is trying to get your desired heir to inherit the best titles. Or set you r primary heir up to be strong enough to beat their siblings and claim the titles they have claims on when you play as your primary heir after you die. Or yes, potentially imprison your other kids until they die or assign them as a leader in battle and hope they die to minimise the partition. Murder is an option, too. Or disinheriting them, which costs some renown, I think.

You can also add succession elective laws to specific titles, then the strategy becomes convincing or blackmailing electors to vote for your desired heir.

As you advance through the innovations, you will be able to change your realm's succession laws to eventually have only one heir inheirt everything.

[Dremdin]

For more specific clues on where to start from:
- in the "realm" pannel (top button on the right of your screen), there are a "laws" tab and a "succession" tab. Under the "laws" tab, you can see, and possibly change, the succession law (and read what it does). Under the "succession" tab, you can check in real time who will inherit what if you were to die right now.
- unless your succession law is the top left one (partition confédérée), if you only keep one title of the highest rank (for instance only one duchy or only one kingdom), your realm will remain under your rule, even if some of your personal domain is given to your brothers
- it's not that bad if you do not inherit the whole realm. You get a claim on your brothers' lands, which you can use to wage war to get them back. Another option, if your brothers like you, is to keep them in charge of their own realms, and call them to arms for free when you go to war.