Parma had been one of the North Italian city states - neither the strongest nor the weakest. But it would come to a special prominence: After the great famine in Western Europe 1368, Beggars' hordes were moving through Italy. In 1371, they actually managed to overwhelm the government of Parma, with the help of unemployed mercenaries from the First Aquitainian War. A radical preacher and the government which couldn't pay the mercenaries any more also can be blamed for the revolution. Since the other little states of Italy were in a similar situation, having to fight religious movements and beggars, and often being close to financial collapse, they couldn't interfere. In the city, all the property of the church, all opponents of the new government, and of many people considered to be "too rich" was confiscated and divided among the people.
But the end came soon: In 1395, the north Italian states were hit by the Black Death (although there were some exceptions, like Florence and Savoy). But the divine republic of Parma was especially shocked - their preachers had promised them that God would spare them, which didn't happen. They would never recover from this blow. 1404, Florence invaded the beggar's republic of Parma, annexing it. Florentine settlers would gradually assimilate Parma, until it became just another part of Italy.