Complex sentence: Marcus Maskell Marsh (1904--1983) was an English racehorse trainer whose British Classic wins included the Epsom Derby and St. Leger with Tulyar (1952) and Windsor Lad (1934) as well as the 2,000 Guineas with Palestine (1950).
Split into simpler sentences: Marcus Maskell Marsh (1904--1983) was an English racehorse trainer. His British Classic wins included the Epsom Derby and St. Leger with Tulyar (1952) and Windsor Lad (1934) as well as the 2,000 Guineas with Palestine (1950).