The Zen (often Italianized in Zeno) were a Venetian patrician family, included among the oldest families (the so-called Longhi). They reached the top of the institutions with Renier, doge in the thirteenth century.
Capparo Vivaro, relying on traditions, argues that the Zen descend from the Roman gens Fannia, which also belonged to the Byzantine emperors Zeno and Leo II. A branch of this family went to Padua, and from here to Burano, where its members played the role of tribunes. They arrived in Venice under the dogado of Angelo Partecipazio.
They had vast properties, practically a lordship, between Montegranaro, Francavilla d'Ete and Monteverde, in the Marche, and also dominated, on behalf of the Serenissima, the island of Andros.
The house has left traces in the toponymy: a calle, a small square and a Zen branch are found at the Jesuits, near their palace; in the Frari you have a sotoportego and a further Zen square, with another noble residence nearby.