Who was the strongest ruler of Germany during the middle ages?

Answer 1

This question is some what vague, If by Germany you mean the Holy Roman Empire for example the most noted would be Charlemagne (Charles the Great) who founded the Empire. If however you mean a Ruler after the time the HRE became insignificant Germany was ruled by princes not a single king. Germany would not be reunited until the time of Bismark who in 1871 created a united Germany and Prussia.

Answer 2

This would be very hard to say given it is a eight or nine hundred year period of time and Germany was not a unified state but more of a loose territory of states that together made up the greater "Holy Roman Empire". The Germanic Franks led by Charlemagne (German or French make of this what you will) had one of the largest empires in Europe during this period ruling both modern France and most of modern Germany among others. Charlemagne was also the first Holy Roman Emperor crowned at the pope insistence. Others will claim Otto I the Great was the first real Holy Roman Emperor. Here are a few others you could make an argument for the aforementioned Otto I, Henry III and Frederick Barbarossa.

Answer 3

Otto I the Great was a strong German ruler. Friedrich I Barbarosa was another. There were others. You could look at the link below to see some.

Answer 4

Otto I, the son of Henry I