Major milestones in the life of Dr Mahathir Mohamad, who retires Friday after 22 years as Malaysia's prime minister:

1925: Born on Dec 20, the youngest of 10 children of an immigrant schoolteacher father of Indian descent and a Malay mother.

1953: Graduates as a medical doctor at the King Edward VII College of Medicine in Singapore and returns to the then-British colony of Malaya to work as a government medical officer before going into private practice.

1964: Enters politics (Malaysia gained independence in 1957) as a member of parliament for the United Malays National Organisation (Umno).

1969: Expelled from the party after criticising premier Tunku Abdul Rahman for failing to stand up for ethnic Malays in the face of economic dominance by the ethnic Chinese minority.

1970: Writes "The Malay Dilemma", criticising Malays for failing to progress.

1972: Rejoins Umno after being rehabilitated when Tunku resigns.

1974: Elected as member of parliament again and begins rapid rise through the ranks, holding several ministerial posts.

1978: Becomes deputy president of Umno.

1981: Takes over as Malaysia's fourth prime minister.

1982: Introduces the "Look East" policy, turning to Japan as an economic role model.

1985: Malaysia sinks into recession. Mahathir imposes fiscal austerity measures and relaxes affirmative-action laws favouring Malays.

1986: Mahathir's first deputy Musa Hitam resigns due to personal conflict.

1987: Mahathir narrowly fends off a challenge for Umno presidency in April from his then-trade minister Razaleigh Hamzah.

1987: Government swoops on the opposition in October, detaining more than 100 people and suspending three newspapers, to curb a rise in racial tension over the issue of Chinese education.

1988: Cracks down on the judiciary after the high court supports a petition by his opponents within Umno. The country's top judge is sacked.

1989: Mahathir undergoes heart bypass operation.

1991: Outlines his "Vision 2020" plan to make Malaysia a developed nation by that year.

1993: Strips the country's monarchs of their legal immunity from prosecution after a state sultan allegedly beat up a field hockey coach in his palace.

1994: Slaps a seven-month ban on awarding of government contracts to British firms in protest at British media claims that his government was corrupt.

1997: Hosts a summit of Asean leaders. Despite western protests over Burmar's human rights record, he backs Rangoon's entry into Asean to mark the grouping's 30th anniversary.

1998: Imposes capital controls and pegs the ringgit at 3.80 to the dollar as the economy plunges into recession due to the Asian financial crisis.

1998: Sacks his deputy and finance minister Anwar Ibrahim on grounds of sexual immorality. Anwar was later tried and sentenced to a total 15 years in jail for abuse of power and sodomy.

2002: Announces his unexpected resignation in an emotional speech at Umno's general assembly in June. He later makes plans to step down by October 2003, and endorses his deputy Abdullah Ahmad Badawi as his successor.

2003: Hosts summits of the Non-Aligned Movement in February and the Organisation of Islamic Conference in October ahead of his retirement. - AFP