You searched for: “caput mundis
caput mundi (s) (noun), caput mundis (pl)
A reference to the head of the world or the center of the world: Caput mundi was a reference to imperial Rome which was carried over to the papacy in medieval times.

Those who to stir up enthusiasm for their hometowns may use caput mundi in the same way the Romans did; that is, Rome was considered the capital of the world.