Complex sentence: Léonard Steyaert (born 28 May 1907, date of death unknown) was a Belgian boxer who competed in the 1928 Summer Olympics and won the bronze medal in the middleweight class.
Split into simpler sentences: Léonard Steyaert (born 28 May 1907, date of death unknown) was a Belgian boxer who competed in the 1928 Summer Olympics. In 1928 he won the bronze medal in the middleweight class.