Complex sentence: As a strong advocate of colonial expansion he was also a bitter enemy of Britain, and he was to a large extent responsible for the anti-British feeling of German Chauvinism during the last years of the 19th century.
Split into simpler sentences: As a strong advocate of colonial expansion he was also a bitter enemy of Britain. He was to a large extent responsible for the chauvinistic anti-British feeling of the last years of the 19th century.