controlling Gavelkind Succession

[DreadLindwyrm]

"Gravelkind".

Given that cities are almost always just a single holding, "gravelkind" is just primogeniture, basically.

Gavelkind, not gravelkind. As in gavel, the thing used by a judge or auctioneer to keep order.

Does anyone knows why are cities always open elective? Some history insight?

Merchant republics and elected mayors rather than hereditary noble estates.