A group of more than 170 islands spread over an area of the South Pacific roughly the size of Japan, Tonga is the last Polynesian monarchy.
A deeply conservative, Christian country, Tonga voted in its first popularly elected parliament in 2010, ending 165 years of feudal rule.
In 2015, the country elected its first non-noble prime minister.
A former British protectorate, Tonga became fully independent in 1970, though it was never formally colonised.
Tonga has no strategic or mineral resources and relies on agriculture, fishing and the money sent home by Tongans living abroad, many of them in New Zealand. Unemployment is high, particularly among the young.
Endowed with tropical beaches, rainforest and active volcanoes, it has a developing tourist industry - its main source of hard currency.
Kingdom of Tonga
Area 748 sq km (289 sq miles)
Major languages Tongan, English
Major religion Christianity
Life expectancy 70 years (men), 76 years (women)
Head of state: King George Tupou VI
George Tupou VI succeeded to the throne on the death of his elder brother, the bachelor George Tupou V, in March 2012.
King George Tupou V ushered in parliamentary democracy in 2010, ending centuries of feudal dominance of government.
Prime minister: 'Akalisi Pohiva
Veteran leading pro-democracy campaigner 'Akalisi Pohiva became the country's first non-noble prime minister in January 2015.
Having spent nearly three decades in opposition, he was elected in the wake of parliamentary elections two months earlier.
Half of all incumbent MPs lost their seats in the vote, amid concern about sluggish economic growth and high unemployment.
In August 2017 King Geroge Tupou VI dismissed Pohiva as prime minister and dissolved the parliament amid accusations of removing some of king's powers. Following his party's victory in the general election Pohiva was re-elected prime minister in December 2017.
State radio and TV tend to be pro-government, while private broadcasters offer little independent local coverage.
Privately-owned newspapers carry opposition views, but journalists can face harassment and threats of criminal charges. A Department of Information oversees all media reporting, US-based Freedom House notes.
Some key events in Tonga's history:
1616 - Dutch explorers are the first Europeans to visit Tonga.
1773-77 - British explorer Captain James Cook visits Tonga three times.
1830s - Wesleyan missionaries convert paramount chief Taufa'ahau Tupou who in turn converts fellow islanders.
1875 - Taufa'ahau Tupou assumes the name of George Tupou I and establishes Tongan monarchy.
1900 - Tonga becomes a British protected state but is not formally colonised.
1970 - Tonga ceases to be a British protectorate and becomes fully independent within the British Commonwealth.
2010 November - First vote for a popularly elected parliament.