The advent of Renier Zeno in 1253 to the Ducal throne was marked by a further suppression of popular rights. It was decreed that, before publication of the new Doge’s name by the electoral college of the forty-one, the people should swear to accept their choice. The blow was accompanied by an application of Napoleon’s favourite device--Amuse the people with toys. A magnificent tournament and gorgeous processions celebrated the new Doge’s election and enthronement. Zeno was a tried administrator and soldier; he had commanded as _podestà_ the Bolognese forces at the siege of Ferrara. Nor did his military genius rust for lack of use. In his troublous reign of sixteen years began the long and exhausting struggle with Genoa for naval supremacy and commercial monopoly. At St Jean d’Acre was a church dedicated to St Sabbas, and there the Genoese and Venetians were wont to worship in common--each, however, claiming exclusive ownership in the building. A dispute as to an alleged Venetian corsair captured by the Genoese ended in a riot. The Genoese raided the Venetian ships, sacked their quarter of the city, and burnt the church. After vain and perhaps insincere attempts at pacification Venice determined to wreak vengeance on her rival, and in 1286 Lorenzo Tiepolo was despatched with a fleet to Acre. He spoiled and burned the Genoese vessels in harbour, landed and destroyed part of their settlement, and after some fighting captured their stronghold, the castle of Mongioia. They sued for a truce, which was granted for two months. As trophies and palpable sign of his success, Tiepolo sent to Venice the short column of porphyry which now stands at the south-west angle of St Mark’s known as the _Pietra di Bando_, (proclamation stone), because there were promulgated the laws of the Republic; and the two beautifully decorated, square, marble columns that stand side by side facing the Piazzetta, over against the south side of the church.