Over the last four decades, Professor Jeremy Johns has been a leading researcher on the history of the Islamic Mediterranean, particularly Sicily, and a pillar of the advanced study of Islamic art and archaeology at Oxford. This conference, organised to mark his retirement, brings together speakers from among his former students and closest colleagues to celebrate his career. The topics, ranging from Europe to Southeast Asia and from early Islam to the modern era, reflect the breadth of his interests and his impact on the field. We hope the event will be a fitting testament to a scholar – to quote Malaterra’s words about Roger I of Sicily – “most eloquent in speech and cool in counsel”.