After Antipope Theodoric was arrested and imprisoned in January, 1101, the followers of Antipope Clement III, encouraged by Henry IV, Holy Roman Emperor -- gathered in the Basilica of SS. XII Apostoli in Rome and elected Cardinal Alberto -- an Italian -- who was the Cardinal Bishop of Santa Rufina as Pope Adalbert (also called Pope Albert).

The Lives of the Popes in the Middle Ages -- The Popes of the Gregorian Renaissance, St. Leo IX to Honorius II -- 1049 - 1130 -- Vol. VIII -- 1099 - 1130 -- pg. 14 says:

Again there was a mock election in St. Peter's. But no sooner did word of what was there being done spread abroad than the whole



city was in an uproar, and the crowd rushed to the Basilica. In great alarm the assembly hastily broke up; but while Albert, the newly elected Antipope, who was the Bishop of Sabina, contrived to make his escape to the Basilica of St. Marcellus, many of his party were seized and were roughly handled. A sum of money quickly bought Pope Albert from his patron. He was stripped of the pallium that he had just assumed, put on a horse behind its rider, and taken before the rightful Pope -- Pope Paschal II -- at the Lateran. After a short incarceration in a tower, he too was sent to a Monastery and ended his days as a Monk at St. Lawrence's at Aversa. Albertus (Gegenpapst)

Albert (antipape) Adalbert