Medalling in two Olympic Games in 1988 and 1992, he was a World (short course), European and Commonwealth champion in his specialist event, the 200 metres breaststroke.

However, he sustained a leg injury during the Olympics which impaired his performance in the 100m final where he finished 7th, half a second slower than his heat time.

He broke three world, ten European, nine Commonwealth and seventeen British records during his career and won 17 major championships.

[10][11][12][13][14][15][16] Gillingham was appointed Member of the Order of the British Empire (MBE) in the 1993 New Year Honours for services to swimming,[17] and retired from full-time competitive sport in 1996.

Recently, Gillingham took part in a scheme called Young Ambassadors, promoting youth sport development in the North East of England at Loughborough.