Europe in 1300
Italy
Like Germany, Italy was not a nation at this time, nor would it be until 1860. There are three main divisions of Italy you should keep in mind: north, central and south.
The south is the easiest, as it consisted of the Kingdom of Naples, which had in 1300 only recently been split away from Sicily. This had become a kingdom back in the early 1100s when the whole region was ruled by its Norman conquerors. Yes, the same Normans who had conquered England. By our course, Norman rule had collapsed. They'd been followed by the rule of Frederick II, then by the Angevin Charles. In 1288 there'd been a major revolt in Sicily and that war was still winding down in 1300. The result would be a split into two kingdoms. Sicily went to the kings of Aragon while Naples went to Anjou. These two, Aragon and France, would continue to have ambitions in southern Italy that from time to time affected the entire peninsula.
The center was more united, for this was the area of the Papal States. In 1300 it was relatively well controlled from Rome, but that would soon fall apart almost completely because of the removal of the papacy to Avignon followed by the Great Schism. Until around 1440 or so, the Papal States were little more than a nest of warring local lords and towns. After the reassertion of papal control, the Papal States became the focus of papal ambitions for territorial expansion, so we'll hear quite a bit about them, especially along the northern borders. It's worth mentioning that the city of Rome itself was not a significant power, though its leading families, by virtue of their influence on the papacy, do emerge front stage from time to time.
The north was the most complex, being comprised of various independent powers. Chief among these were Venice, Florence, Milan, Genoa and the county (later duchy) of Savoy. Behind them were a good dozen or so other towns serving variously as players or prizes. Those you'll likely hear about include Siena, Pisa, Bologna, Ferrara, Lucca, Brescia, and Verona.