Adrian, in a last frantic attempt to prevent bloodshed, throws
himself in front of Rienzi's horse, imploring the Tribune to
allow him to try once more to conciliate the rebel nobles. But
Rienzi utterly refuses to yield again to his entreaties, and
marches calmly on, accompanied by the people chanting the last
verse of their solemn war-song.

The fourth act is played in front of the Lateran church. The
battle has taken place. The barons have been repulsed at the
cost of great slaughter. But notwithstanding their losses
and the death of their leader, the elder Colonna, the nobles
have not relinquished all hope of success. What they failed to
secure by the force of arms, they now hope to win by intrigue,
for they have artfully won not only the Pope, but the Emperor
also, to uphold their cause and side with them. The people, who
have just learned that the Pope and Emperor have recalled their
legates and ambassadors, are awed and frightened. Baroncelli and
Cecco, two demagogues, seize this occasion to poison their fickle
minds, and blame Rienzi openly for all that has occurred. Their
specious reasoning that the Tribune must be very wicked indeed,
since the spiritual and temporal authorities alike disapprove
of him, is strengthened by the sudden appearance of Adrian,
who, wild with grief at his father's death, publicly declares
he has vowed to slay the Tribune. The people--who, lacking the
strength to uphold their convictions, now hate their leader
as vehemently as they once loved and admired him--are about
to join Adrian in his passionate cry of 'Down with Rienzi!'
when the cardinal and his train suddenly appear, and march into
the church, where a grand 'Te Deum' is to be sung to celebrate
the victory over the barons.