While they claimed to be the leader of all of Europe, what were the real borders of the effective power of the German emperors?

The effective power of the German emperors, also known as the Holy Roman Emperors, was primarily concentrated in Central Europe. The borders fluctuated over time due to political changes, but generally included the following regions:

1. Germany: The core of the Holy Roman Empire was the Kingdom of Germany, which included most of modern-day Germany, Austria, and parts of Switzerland.

2. Italy: The emperors also claimed power over the Kingdom of Italy, but their control was often nominal, especially in the south and during the later periods of the empire.

3. Burgundy: The Kingdom of Burgundy, which included parts of modern-day France, Switzerland, and Italy, was also part of the empire.

4. Other regions: At various times, the emperors also held power over other regions, such as the Kingdom of Bohemia and parts of modern-day Poland, Belgium, and the Netherlands.

However, it's important to note that the power of the emperors was often limited by the autonomy of the empire's constituent states, especially the powerful duchies and bishoprics. The emperors often had to negotiate with these states to exercise their power, and their ability to control the empire's borders was limited.