Complex sentence: In 1936, he revived the rank of field marshal, the highest and most powerful military rank in Germany, originally only for the use of the Minister of War and Commander-in-Chief of the Army.
Split into simpler sentences: In 1936, he revived the rank of field marshal. It was the highest and most prestigious military rank in Germany, originally only for the use of the Minister of War and Commander-in-Chief of the Army.