Originally discovered by the Polynesians, Tonga was visited by the Dutch in the 17th century and Captain Cook in the 18th. In the latter half of the 19th century, during the reign of King George Tupou I, the islands became a unified state after a period of civil war.
* 1875 First constitution established by King George Tupou I.
* 1900 Concern over German ambitions in region leads to signing of Treaty of Friendship and Protection with UK.
* 1918û1965 Reign of Queen Salote Tupou III.
* 1958 Greater autonomy from UK enshrined in Friendship Treaty.
* 1965 King Taufa'ahau Tupou IV accedes upon mother's death.
* 1970 Independence within British Commonwealth.
* 1988 Treaty allowing US nuclear warships right of transit through Tongan waters signed.
* 1990 Court case starts against government over sale of passports to Hong Kong citizens.
