Sebastiano Ziani was a famous leader of Venice

Venice

Venice is a city in northern Italy which is renowned for the beauty of its setting, its architecture and its artworks. It is the capital of the Veneto region...

, and was Doge

Doge of Venice

The Doge of Venice , often mistranslated Duke was the chief magistrate and leader of the Most Serene Republic of Venice for over a thousand years. Doges of Venice were elected for life by the city-state's aristocracy. Commonly the person selected as Doge was the shrewdest elder in the city...

 from 1172 to 1178. Ziani was one of the greatest planners of Venice.

During his short term as Doge, Ziani divided the city-state into many districts. He realised that the government headquarters were too close to the shipyard. As such, they were affected by the noise from the shipyard. Ziani resolved this problem by donating a piece of land to the city-state and relocating the shipyard in it.

He also hosted Pope Alexander III

Pope Alexander III

Pope Alexander III , born Rolando of Siena, was Pope from 1159 to 1181. He is noted in history for laying the foundation stone for the Notre Dame de Paris.-Church career:...

, the Emperor Frederick I, and the delegation of William II of Sicily

William II of Sicily

William II , called the Good, was king of Sicily from 1166 to 1189. William's character is very indistinct. Lacking in military enterprise, secluded and pleasure-loving, he seldom emerged from his palace life at Palermo. Yet his reign is marked by an ambitious foreign policy and a vigorous diplomacy...

 for the signing of the Treaty of Venice

Treaty of Venice

The Treaty or Peace of Venice, 1177, was an important peace treaty between the papacy and its allies, the north Italian city-states of the Lombard League, and Frederick I, Holy Roman Emperor...

in July 1177.