La Serenissima — the utmost serene — is one of the many nicknames for Venice, and especially the Venetian Republic which existed from the late 600s until 1797.
The fall of Venice on May 12th, 1797, was the result of a war that the Republic of Venice formally wasn’t even party to.
The Consiglio Maggiore – or the Great Council – was the highest authority of the Venetian Republic. It was not, however, an elected body. It was the entire electorate.
The doge was the elected head of the Venetian Republic. He was elected for life by an arcane process that also included drawing lots.