Europe in 1300
The Holy Roman Empire
I've already briefly described the Holy Roman Empire; here, I offer this map as a way to visualize it. It's the green-blue area in the middle of the map.
On this map it looks like a single entity, but the preceeding pages should dispel that notion. Nevertheless, the Emperor exercised at least a theoretical jurisdiction over this entire area, from Holland and Pomerania in the north; Luxembourg, Lorraine and Savoy on the west; Pomerania, Silesia, Moravia and Austria to the east; down into Italy as far as Venice, Bologna, and Perugia to the south. It included most of the richest cities of Europe and had a population far greater than any other state. In theory, the Emperor should have been by far the most powerful man in Europe.
In reality, the emperors of our period spent much of their time trying to hang on to what shreds of authority they could. They were perpetually broke (well, so were many other monarchs), constantly embattled, and never more than an election away from having their family turned out of imperial power altogether.
Imperial Dynasties
Speaking of which, it's worth listing our emperors here, according to their dynasty. Just for reference.