Emerging from his solitude Rienzi journeyed to Prague, which he reached in July 1350, and threw himself upon the protection of the emperor Charles IV.
At Avignon, where he appeared in August 1352, Rienzi was tried by three cardinals, and was sentenced to death, but this judgment was not carried out, and he remained in prison in spite of appeals from Petrarch for his release.
Giving him the title of senator, he sent him to Italy with the legate, Cardinal Albornoz, and having collected a few mercenary troops on the way, Rienzi entered Rome in August 13 54.
Rienzi attempted to address them, but the building in which he stood was fired, and while trying to escape in disguise he was murdered by the mob.
Accepting this, he remained actively employed until 1839, when he made his first visit to Paris, taking with him an unfinished opera based on Bulwer Lytton's Rienzi, and, like his earlier attempts, on his own libretto.