Answer
Daley Thompson has never held the World, Commonwealth, Olympic and European titles simultaneously. He has won the Olympic title twice, in 1980 and 1984, and the World title once, in 1983. He has also won the Commonwealth title three times, in 1982, 1986 and 1990, and the European title twice, in 1982 and 1986. However, he has never won all four titles at the same time.