Final answer:
The German leader that used the power of the church to unify the German kingdoms under his own rule was Otto I, also known as Otto the Great. He was German king from 936 and the Holy Roman Emperor from 962 to 973.
Step-by-step explanation:
The leader who utilized the church to unify German kingdoms under his power was Otto I. Born in 912 and also known as Otto the Great, he was the German king from 936 and the Holy Roman emperor from 962 until his death in 973. He used the church power to centralize his authority and unify different German states.
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