The prospect of unification of the Yemen in 1990 prompted the beginning of work on this collection which is likely to remain unrivalled as the definitive source work for the history of the region. Five years of research, including privileged access to ancient and fragile archives now closed to public view, have culminated in an extensive collection of key original documents reproduced in facsimile from British government files, detailing the history of the affairs of the Imams of Sana'a and the Aden Colony and Protectorate. The important historical material in this work provides scholars, administrators and diplomats with an extensive and importance repertoire of primary documents reflecting the history of the Yemen. The editor, the late Doreen Ingams, and her husband Harold, the distinguished administrator, traveller and writer, first came to Aden in 1934 and were the first Europeans to live in Hadhramawt.