Complex sentence: He began working as a assistant physician at the Rotunda Hospital in 1851, and in November 1875 he was elected master of hospital, considered the leading expert on gynaecology in the country at the time.
Split into simpler sentences: He began working as a assistant physician at the Rotunda Hospital in 1851. In November 1875 he was elected master of hospital, and was considered the leading expert on gynaecology in the country at the time.