A chronology of key events
1907 - Ugyen Wangchuk is chosen as hereditary ruler
1910 - Treaty signed with British giving them control over Bhutan's foreign relations
1949 - Treaty signed with newly-independent India guaranteeing non-interference in Bhutan's internal affairs, but allowing Delhi influence over foreign relations
1952 - Reformist monarch Jigme Dorji Wangchuk succeeds to throne
1952 - National assembly established
1958 - Slavery abolished.
1959 - Several thousand refugees given asylum after Chinese annex Tibet
1964, 1965 - Prime minister killed in dispute among competing political factions. Unsuccessful attempt to assassinate monarch.
1968 - First cabinet established
1971 - Bhutan joins the UN
1972 - King Jigme Dorji Wangchuk dies and is succeeded by his son, Jigme Singye Wangchuk, who continues policy of cautious modernisation
1989 - Nepali ceases to be a language of instruction in schools.
1990 - Violent ethnic unrest and anti-government protests in southern Bhutan pressing for greater democracy and respect for Nepali rights. Bhutan People's Party begins campaign of violence. Thousands of ethnic Nepalis flee to Nepal.
1992 - Leader of illegal Bhutan People's Party sentenced to life imprisonment.
1993 - Bhutan and Nepal try to resolve refugee problem.
1998 - King cedes some powers to national assembly, giving up role as head of government; cabinet now elected by assembly; famous "Tiger's Lair" Buddhist monastery damaged by fire.
1999 - Limited television and internet services allowed; several dozen political prisoners released.
2002 December - First draft of a new Constitution presented; it envisages Bhutan becoming a parliamentary democracy with a constitutional monarchy.