Samoa was first noticed by a European in 1722 when the Dutchman Jacob Roggeveen sighted it. Bougainville later stopped off at the islands in 1768. The first British contact was when John Williams and Charles Barf arrived as missionaries from the London Missionary Society.
Commercial connections were attempted by J. C. Godeffroy and Son but these were taken over by a German Trading Company who established a permanent depot on the islands that helped make them a popular trading post in the Pacific.
Anglo-German relations were tense in this period which was encapsulated within the Treaty of Berlin declarations in 1889 which clarified that Samoa was to retain its political independence under its own King with advice from the British, German and American consuls. This was the so-called Tripartite Treaty
The outsider influence got caught up with internal Samoan politics. There was a civil war in 1893/4 and a more deadly one in 1899 that led to serious political disagreements between the Tripartite members. In particular, the British and Americans were unhappy that a German backed surrogate had seized power. On March 15th the American and British Navies bombarded Apia to intimidate the Samoan King. British and American troops landed in the city, but they were unable to pacify the interior. All sides agreed to a ceasefire and a newly demarcated zones of control were assigned. The British backed the American acquisition of some of the Eastern islands whilst the Germans took the Western ones.
During the First World War, New Zealand forces entered and seized the German controlled portion of the island. This was formalised after the war when New Zealand was awarded the League of Nations Mandate for what was now known as Western Samoa.
The League of Nations Mandate was transferred in to a United Nations after World War Two and in 1947 the Samoan Legislative body was altered so that it was composed of a Samoan majority with substantial powers.
Western Samoa was granted independence in 1962 and joined the Commonwealth in 1970.