The Austrians soon lost control of the city: the Venetian Arsenal was seized by revolutionaries, and, under the direction of Manin, a civic guard and a provisional government were instituted.

But after the Piedmontese defeat at Custoza, and the armistice in which King Charles Albert abandoned Lombardy and Venetia to Austria, the Venetians attempted to lynch the royal commissioners, whose lives Manin saved.

Early in 1849, Manin was again chosen president of the Republic, and conducted the defence of the city, with the citizens fighting back the reoccupation.

On 26 May, the Venetians were forced to abandon Fort Marghera; food was becoming scarce; on 19 June, the powder magazine blew up; and in July, cholera broke out.

The Austrian batteries, subsequently, began to bombard Venice, and when the Sardinian fleet withdrew from the Adriatic, the city was also attacked by sea in demagogues.

There, he became a convert from republicanism to monarchism, being convinced that only under the auspices of King Victor Emmanuel could Italy be freed, and together with Giorgio Pallavicini and Giuseppe La Farina, he founded the Società Nazionale Italiana, with the object of propagating the idea of unity under the Piedmontese monarchy.

[4][3] The gondola carrying his coffin was decorated with a bow "surmounted by the lion of Saint Mark, resplendent with gold", bore "the Venetian standard veiled with black crape", and had "two silver colossal statues waving the national colours of Italy".

After the meeting, Cavour wrote that Manin had talked about "l'unità d'Italia ed altre corbellerie" ("the unity of Italy and other nonsense").