This series consists of the records of four different bodies: minutes, reports and correspondence of the first Colonial Defence Committee, minutes and papers of the the Royal Commission appointed to enquire into the Defence of British Possessions and Commerce Abroad (Carnarvon Commission), minutes and papers of the second Colonial Defence Committee, and minutes and papers of the CID's Colonial Defence Committee, later renamed the Oversea Defence Committee, Additionally, there are War Office memoranda on colonial defences and various related reports.
Topics covered by the first Colonial Defence Committee were defence of the colonies and seaborne trade and the defence of colonial ports. The Royal Commission appointed to enquire into Defence of British Possessions and Commerce Abroad (Carnarvon Commission) addressed matters of colonial defence, issues arising from the international crisis, seaborne trade, and specifically the defence and provision of coaling stations in the colonies.
Topics covered by the second Defence Committee and by the CID's Defence Committee, later the Oversea Defence Committee, included those which occupied the Committee's predecessors, together with the composition and organisation of local forces and the provision for overseas commands, principally in non-self governing territories.