Known as Porta Tosa until the end of the nineteenth century, then as Porta Vittoria, it was one of the 11 gates in the Spanish walls of Milan. It opened the way to the East.

The name of Porta Tosa, today's Porta Vittoria of which only customs duties remain in Piazza 5 Giornate, was given by a medieval bas-relief that until 1848 was above the arch of the Porta and which today is exhibited in a room of the Museum of Ancient Art of the Castello Sforzesco. It depicts a woman with legs apart with a razor in her right hand in the act of shaving her pubis, this was a punishment inflicted on adulterers and prostitutes.

Several legends are told about the meaning of this bas-relief. In 1162 Milan was besieged by the troops of Frederick Barbarossa and it is said that a girl, to distract the enemy soldiers, showed herself on the balcony with her clothes raised in the act of shaving.

Others say that some Milanese citizens went to Constantinople to ask for help to rebuild the city that Barbarossa had razed to the ground. The Empress of Constantinople Leobissa opposed granting the aid. The Milanese, as a sign of mockery, depicted her as a prostitute in the act of shaving and placed her on the door that most of all gave to the East.