The Domination Victory is one of the Victory Conditions in Civilization VI, and a strong military taking over other Capitals will win you this type of victory.
Description
To achieve a Domination Victory, you must conquer the 
Capital of every other civilization.
- A strong military is highly recommended.
Notes
It doesn't require outright Warmongering, but is perhaps best suited to that playstyle. In order to win a game this way, you must capture and hold the Capital Cities of all other Civs in the game. Learn some tips on preparing your units for war and how you can take over the world by dominating every Civ on the planet.