Complex sentence: Johann Rottenhammer, or Hans Rottenhammer, (1564--1625) was a German painter, born in Munich, where he studied until 1588 under Hans Donauer the Elder.
Split into simpler sentences: Johann Rottenhammer, or Hans Rottenhammer, (1564--1625) was a German painter. He was born in Munich, where he studied until 1588 under Hans Donauer the Elder.