The Sultan’s long-standing desire to expand his influence in northern Oman precipitated a little-known insurgency in 1957 that highlighted the weaknesses of his rule. The insurgency had enduring characteristics including the influence of foreign support for the rebels and Britain’s unheralded assistance. Maintaining a silent relationship based on covert support became a notable characteristic of British policy in Oman over the following decades. The most significant long-term legacy of the insurgency was Whitehall’s realisation that steps had to be taken to amalgamate Oman’s security forces which led to the establishment of the Sultan’s Armed Forces which were commanded by British officers for decades. The insurgency led to the signing of a defence agreement which committed the British government to significant expenditure.