The Venetian patriot Daniele Manin (1804-1857) labored for the liberation of Venice from Austria and made an important contribution to the unification of Italy.

Daniele Manin was born on May 13, 1804, the son of a converted Jew who adopted the name of the patrician family that had sponsored him. Manin studied law at the University of Padua and then took up practice in Venice. As his practice grew, his reputation as a brilliant and profound jurist grew with it.

Manin's first act in the cause of liberation was the presentation of a petition in 1847 to a body called the Venetian Congregation, a purely advisory assembly that the Austrian government permitted to gather precisely because it had no power at all. The petition, addressed to the Emperor, listed the grievances of the Venetian people. Manin hated the Austrian domination of Venice and was injudiciously frank about it.

On Jan. 18, 1848, he...