Mizukage

The is the leader of Kirigakure. There have been five official Mizukage, though only two have been seen in the series. Their word holds sway over all political and military issues that present themselves regarding Kiri and its inhabitants. The Mizukage's residence, where they inhabit and hold office, is the widest and largest landmark in Kirigakure, bearing the kanji for.

Fourth Mizukage
He was controlled by Madara Uchiha who could be called the "real" Fourth Mizukage.