Pope Gennarus I

Pompeo Colonna, more commonly known as Pope Gennarus I, was the antipope in control of the Catholic Church between 1527 and 1538, in Season 2 of Brazilian's Varna series.
In 1527, the Italic Union invaded the State of the Church and besieged the city of Roma. On September 6th, exactly 10 years after Italia sacked Cairo, Italia sacked Roma. The news spread throughout Europe in mere hours, as a conclave was held, since the Pope at the time, Clement VII, had "gone missing". The Conclave of 1527 saw Cardinal Pompeo Colonna become the head of the Catholic Church, and he styled himself as Pope Gennarus I. Gennarus signed an agreement with the Italic king, whereby Italia would annex Umbria from the Papal state. In February 1533, it was revealed that Gennarus' predecessor Clement had survived the Sack of Roma. Therefore, Clement was technically the legitimate Pope, however the news of his survival was only known to Gennarus, not the other cardinals.
King Henry VIII of England came to Roma in April 1533, asking for Papal permission to divorce his wife, his elder brother's widow. Gennarus declined. The next year, after Gennarus decided to excommunicate Clement, England joined several states of the Holy Roman Empire in abandoning the Catholic Church.
In a public announcement in 1536, the Lombard Captain & Defender Lorenzo Furlan publicly announced to Italy and Europe that Pope Clement VII had survived the Sack of Roma. Two years later, in April 1538, Lombardy officially declared war on Gennarus' Papacy, in order to reinstate the legitimate pope. This quest, known as the Italian Schism, was soon joined by Brescia and the Tuscan states. The expedition was a quick one, since Papal troops recognised Clement as their Pope, and therefore offered no resistance to, and even joined the army invading Roma from the north. In a short battle, between troops loyal to Gennarus and the Lombard First Army, Gennarus was killed and his Papacy ended with it.