Italy
Naples and Sicily in the 14th Century
In 1300 the War of the Sicilian Vespers was still going on. This war had begun in 1284 with a revolt against the rule of Charles of Anjou, who had tried very hard to restore the Kingdom to its former glories. He was even on the verge of an invasion of the Byzantine Empire when the rebellion broke out. He spent the rest of his reign trying to restore order. The war was actually just winding down, with a peace treaty signed in 1302. Nevertheless, the war had devastated the kingdom and made a shambles of central authority.
One of the most important consequences of the war was that it brought the Kingdom of Aragon into Italian politics, for the Sicilians who rebelled had turned to Aragon for help. They actually acclaimed Peter of Aragon as the King of Sicily. Charles was brother to the King of France, and so both Spain (Aragon) and France were entangled in the politics of southern Italy. In the ensuing twenty years the individual leaders changed but France and Aragon continued to be deeply involved. Moreover, the papacy got involved by declaring a crusade against the rebels and against their Aragonese supporters. During the course of the war, Aragon became entrenched in Sicily and the French in Naples. The treaty in 1302 formally recognized the two as separate kingdoms.
The Angevin Kings of Naples
The most important of the 14th century rulers of Naples was Robert II, called Robert the Wise. He was signoria in Florence for a time, when that city was riven by faction, and he was papal vicar in Romagna, in the Papal States. From early on, therefore, the southern kings were involved in northern politics as well. Robert was the chief military force opposing Emperor Henry VII's advance through Italy and was largely responsible for driving him back north again. Robert also became a Senator in Rome and was lord of Genoa and Brescia. For a time during his rule, Robert was the single most powerful man in all of Italy. Sicily held out, though, still under Aragonese rule.
Robert was succeeded by his granddaughter Joanna I. Her succession was disputed, but she managed to survive her rivals. Her first husband was Andrew of Hungary, who was assassinated a year after their marriage. This managed to bring Hungary into the politics of the south, including an invasion. She married twice more but was childless and ended by adopting Louis I of Anjou, a younger son of the king of France, as her heir. She did this in part because she was a supporter of the papacy at Avignon. This in turn caused the Roman pope Urban VI to support her enemies and to recognize Charles of Durazzo, her closest male heir, as her successor. This naturally led to more war.
Charles of Durazzo led a successful rebellion. He captured Joanna in 1381 and had her strangled in 1382. Il Regno now had multiple claimants, including Aragon, France, Hungary, and Charles himself. Charles managed to hang on, though, and was eventually succeeded by his son Ladislas.
King Ladislas was an ambitious and skillful fellow who had claims to Hungary and even inherited the title of King of Jerusalem. He died in 1414 and was succeeded by his sister Joanna II (also, Joan or Giovanna).