The ceremony of the Sénsa (Ascension in Venetian), traditionally also called Marriage with the Sea or Blessing of the Sea, is celebrated in May on the day of the Ascension in the mouth of the port -inlet of San Nicolò (island of Lido di Venezia). It was established in the year 1000 by the Doge Pietro Orseolo II to commemorate an important political event in the history of the Republic which marked the beginning of the Venetian success in the Adriatic Sea. On May 18, 999, Ascension Day, the Doge won the war against the Slavs in Dalmatia, thus sanctioning the maritime dominance of Venice.
The festival has not only a political-religious dimension, but also an accentuated propitiatory character towards the sea (hence the name of Blessing of the Sea), an element that also emerges from the ancient prayer which in one of its verses reads <>. At the end of the ritual, holy water was poured, as still happens today, into the sea in order to exorcise the dangers of navigation. This ancient Venetian ceremony takes place in the place where the calm and safe waters of the lagoon meet and mix with those of the sea, a potentially hostile and dangerous element and therefore capable of becoming an enemy for man.