For 150 years after 1820, Oman and the littoral sheikhdoms of the Arabian Gulf were known respectively as Trucial Oman and the Trucial States. This reflected the series of agreements beginning in 1820 progressively extending British control of the external policies of the area, leaving domestic and internal affairs in the hands of the traditional rulers. The trucial system was imposed initially to put down piracy by the Qawasim whose depredations on British trade with India reached a climax at the beginning of the nineteenth century. For many years an accepted version, the allegations of piracy have recently been challenged; this thesis seeks to investigate the issue using archive material from the Bombay Presidency and from the Cairo Citadel, material not previously investigated. It is the writer's contention that the traditional justification for British intervention and control of the Gulf, namely piracy, does not take into account the influence of Wahhabism or Anglo-French rivalry dating from the Egyptian campaigns of Napoleon. Thus, the trucial system rested on a more varied and complex origin than has generally been accepted and reflects more pervasive British interests than a simple humanitarian motive.