R. W. G. Dennis, who was Head of Mycology at the Royal Botanic Gardens, Kew for over 30 years and one of the most eminent and influential British mycologists of the 20th century, died on 7th June 2003 at the age of 92. His immense contributions to fungal taxonomy and plant pathology spanned almost 70 years and covered all major groups of fungi from the tropics to the poles. His seminal studies, frequently based on extensive and pioneering field work, have formed the basis for our understanding of the systematics of many groups, particularly amongst the discomycetes on which he was an acknowledged international authority.