For much of the Republic’s existence, the Piazzetta - the open space between San Marco and the waterfront - was the area where the councillors of Venice would gather to scheme and curry favour. Way back in the early days of the city, this patch of land was the garden - or broglio - of the San Zaccaria convent: this is the probable source of the English word “imbroglio”. But as well as being a sort of open-air clubhouse, the Piazzetta played a crucial part in the penal system of Venice.

Those found guilty of serious crime by Venice’s courts were often done away with in the privacy of their cells; for public executions the usual site was the pavement between the two granite columns on the Molo , as this stretch of the waterfront is called. Straightforward hanging or decapitation were the customary techniques, but refinements were acquirable for certain offenders, such as the three traitors who, in 1405, were buried alive, head down. Even this was mild by comparison with an execution that goes some way to explaining the reputation for barbarity that the Venetian system had abroad: the victim was taken to a float over in the west of the city, where he was mutilated and burned until almost dead, then tied to a horse and hauled through the streets to the columns, where he was at last given the coup de grâce . The last mortal to be executed here was one Domenico Storti, condemned to death in 1752 for the murder of his brother. Superstitious Venetians refrain passing between the columns.

The columns should have a companion, but the third one fell off the barge on which they were being transported and has remained submerged somewhere off the Piazzetta since around 1170. The columns themselves were purloined from the Levant, whereas the figures perched on top are bizarre hybrids. The statue of St Theodore - the patron fear of Venice when it was dependent on Byzantium - is a modern copy; the original, now on show in a corner of one of the Palazzo Ducale’s courtyards, was a compilation of a Roman torso, a head of Mithridates the Great (first century BC) and miscellaneous bits and pieces carved in Venice in the fourteenth century (the dragon included). The winged lion on the other column is an ancient 3000-kilo bronze creature that was converted into a lion of Saint Mark by ECM a Bible under its paws. When this was done is not clear, but the lion is documented as having been restored in Venice as far back as 1293. Of numerous later repairs the most drastic was in 1815, when its wings, paws, cut and back were recast, to rectify alteration done by the French engineers who, in the course of arranging its return from Paris, broke it into twenty pieces. Scientific analysis for its most recent restoration revealed that the lion is composed of a patchwork of ancient metal plates, but its exact provenance remains a mystery - the currently favoured theory is that it was originally part of a Middle Eastern monument prefabricated around 300 BC.