Can inheritance pass on to mother's dynasty?

I'm considering theoretical possibility of using the following scenario to obtain more land for my heir by successfully marrying my other children and then engineering the succession (murdering everyone).

I'm John of Jones dynasty. I have two children - Gary, who is my firstborn son and Lisa, his younger sister. I'm using Agnatic-cognatic Primogeniture. Gary is a genius, so I definitely want him to be my heir.

My neighbour is Ted of Smith dynasty. He also has three children - Alan, Bob and Chris and uses A-C Primogeniture too. He is a duke, so he does not have any Crown Authority.

Now let's say that Bob hates his dad and accepts my invitation to court. I arrange a matrilinear marriage between Lisa Jones and Bob Smith. They produce a son, Nick Jones.

In the meantime I kill Alan Smith, so that Bob becomes his father's primary heir. Soon after, Ted Smith dies too and my son-in-law Bob inherits. His heir is now Nick Jones. So far so good!

Let's suppose that Nick dies before he has any children of his own or brothers/sisters. Who would be Nick Jones' heir? Would the heir be Gary Jones (his mother's brother, of his dynasty) or Chris Smith (his father's and previous liege brother)? Could Gary inherit both my Jones kingdom and his nephew's Smith duchy?


Family tree: X - dead, == - marriage

                                  XTed SmithX
                                  |
                                 -----------------------
XJoe JonesX                      |          |          |
|                           XAlan SmithX    |     Chris Smith
----------------                            |
|              |                            |
Gary Jones     Lisa Jones ============= XBob SmithX
                                |
                            Nick Jones

To answer the original question, the inheritor would never become Lisa Jones, she has no part in the line of succession to the Smith duchy. However, the more important point is that even if Nick inherited, he wouldn't become part of your realm. A better solution would probably be to let Alan inherit while Nick is alive, so that Nick gets a strong claim as a pretender (being the 3rd in line to inherit), which you then press in war. Two possibilities at this point-

If you are a king, Nick will become part of your realm after you win the war due to being a member of your dynasty.

If you are not a king, you can kill off Gary so that Lisa is the inheritor of your realm, then Nick. At this point you could also go with the solution of killing Alan so that you ensure Nick inherits both titles eventually. If you really want to speed it up you can kill of Lisa too, but at this point both realms have basically the same line of succession so they will link up at some point unless you are very unlucky.


In the order of succession, before the deaths, you'll have: 1. Alan Smith 2. Bob Smith 3. Nick Jones 4. Chris Smith

Upon multiple deaths and inheritances, the order should stay the same - therefore Nick Jones' heir should be Chris Smith. But, to be honest, i've seen both scenarios in my games - either there was some change in one of the patches, or idk.

BUT - Easy way to steal the lands of Smiths with the following scenario:

You have Nick Jones, your nephew, and heir to the Smith lands. You give him some land in your kingdom(will only work if you're a higher tier than he is), and, he will be your vassal, and you will be his heir. Afterwards, when he inherits the said Duchy of the Smiths(with or without your help), he will continue to be your vassal, and the Duchy will be part of your demesne, and you should continue to be his heir.