From the end of the Napoleonic Wars in 1815 until World War I in 1914, the United Kingdom played the role of global hegemon (most powerful actor). Imposition of a "British Peace" on key maritime trade routes began in 1815 with the annexation of British Ceylon (now Sri Lanka).[11] Under the British Residency of the Persian Gulf, local Arab rulers agreed to a number of treaties that formalised Britain's protection of the region.