Mr Singh became prime minister in May 2004 after the Congress Party's unexpected success in general elections.
The party's president, Sonia Gandhi, the widow of former prime minister Rajiv Gandhi, shocked her supporters by declining the top post, apparently to protect the party from damaging attacks over her Italian origin.
Mr Singh said his priorities were to reduce poverty and to plough on with economic reforms. He stated a desire for friendly relations with India's neighbours, especially Pakistan.
During his first year in office he held together a coalition which included communist allies and ministers accused of corruption. He continued to pursue market-friendly economic policies and oversaw the introduction of nuclear non-proliferation legislation.
But his promised "New Deal" for rural India - an attempt to raise the poorest citizens out of poverty - has still to bear fruit, and by 2011 he was facing demands for inquiries into a series of financial scandals.
Though Mr Singh has repeatedly promised a crackdown on corruption, his critics say that the accumulation of graft scandals points to a pervasive culture of corruption in his administration.
His government also came under intense pressure after the Mumbai attacks of November 2008, which left nearly 200 people dead and prompted a storm of criticism of security arrangements.
However, Mr Singh's Congress-led coalition then went on to score an emphatic victory at general elections in April and May 2009, coming within 11 seats of winning an absolute majority in parliament.
The emphatic defeat of the opposition Bharatiya Janata Party (BJP) confounded predictions of a close contest.
While still needing the support of some smaller parties, the government looked to be in a much stronger position to pursue economic reforms, particularly against opposition from the left.
Mr Singh made his reputation as a finance minister in the early 1990s, under the Narasimha Rao government, when he was the driving force behind economic liberalisation.
A Sikh born in West Punjab, Mr Singh is a former International Monetary Fund official and governor of India's Central Bank. He was educated at Oxford and Cambridge.
Head of state > Term limit for head of state:
Head(s) of state.
No date was available from the Wikipedia article, so we used the date of retrieval.
- President: Government > Leaders > President
- Prime Minister: Government > Leaders > Prime Minister
- Prime Minister > Summary: Government > Leaders > Prime Minister > Summary
Did you know
- There's a parliamentary seat for every 1.5 million Indians.