Modern study of the Hospitallers, of other military-religious orders and of their activities both in the Mediterranean and in Europe has been deeply influenced by Anthony Luttrell. To mark his 75th birthday in October 2007 twenty-three colleagues from ten different countries have contributed to this volume. The papers include studies on the Hospital in Jerusalem, relations with the Assassins, finances, indulgences, transportation and careers of the brothers and knights. Other studies concern the later Middle Ages, when the Hospitallers had their centre on Rhodes.