Chairman of the General National Congress: Mohamed Magarief
The National Transitional Council, which took control after the popular uprising that ended Colonel Muammar Gaddafi's 42-year-long rule in 2011, handed power to the General National Congress in August 2012.
The 200-seat Congress, elected in July 2012 in the country's first free polls in decades, saw liberal, secular and independent candidates outflank the Muslim-Brotherhood-aligned Justice and Construction Party.
It elected Mohammed Magarief of the small but influential National Front Party as its first chairman. He will serve as Libya's interim head of state until fresh elections are held in 2013, following the drafting of a new constitution.
Mr Magarief, born in 1940 and a native of Benghazi in eastern Libya, was ambassador to India under Col Gaddafi before defecting to the exiled opposition in 1980. He was a leading figure in the National Front for the Salvation of Libya, which made a number of attempts on Col Gaddafi's life.
He beat independent candidate and fellow liberal Ali Zidan by 113 to 85 votes in the Congress chairmanship vote. Mr Zidan was reported to enjoy the support of Mahmoud Jibril's National Forces Alliance, which emerged as the largest group in the Congress, but Mr Magarief managed to win over the Justice and Construction Party and many independents seeking a fresh start, not to mention eastern Libyans anxious not to be excluded from power in Tripoli.
Mr Magarief's first task was to appoint a new government, which will in turn prepare the ground for a constitution and a full transition to democracy.
Prime Minister: Ali Zidan
Mr Zidan was beaten to the chairmanship of the General National Congress in September by Mohamed Magarief, but parliament elected him prime minister a few weeks later in October 2012.
His predecessor, Mustafa Abu Shagur, had failed in two attempts to form a government acceptable to Congress, largely because opposition groups, including the Muslim Brotherhood and the secular National Forces Alliance, felt under-represented.
Mr Zidan's broad-based interim government - which consists of a mixture of liberal figures and Islamists, and also aims to strike a balance between Libya's various regions - was officially inaugurated in November 2012.
Mr Zidan, who is close to the National Forces Alliance of former prime minister Mahmoud Jibril, was a career diplomat who defected from Col Gaddafi in 1980 along with his boss then and now - the ambassador to India, Mohamed Magarief. During the 2011 civil war he was the opposition National Transitional Council's main point of contact with the European Union, and is credited with winning the rebels recognition by several European countries.
Elected to the General National Congress as an independent, he beat the Muslim Brotherhood's Mohammed Harari to the premiership. His interim government faces the challenge of uniting secular, regionalist and Islamic interests in support of a new constitution and parliamentary elections in 2013.
Ousted leader: Colonel Muammar Gaddafi
Until his ouster in 2011, Muammar Gaddafi had been the Arab world's longest-serving leader. A mercurial and shrewd operator, he survived several attempts on his life and reinvented Libya's system of government.
He was captured by rebel fighters on 20 October 2011 in his hometown of Sirte, several weeks after going into hiding. He was shot dead soon after, amid conflicting reports about the exact circumstances.
Inspired by the Egyptian nationalist leader Gamal Abdul Nasser, the colonel came to power in a bloodless coup in 1969 against the ailing King Idris.
Col Gaddafi presented himself as an Arab nationalist, but his attempts to forge unity with other Arab states met with little success. In the 1990s he turned to Africa and proposed a "United States of Africa". The concept later formed the basis of the African Union.
From 1970s onwards, Col Gaddafi angered the West with his support for a broad range of armed groups, including the Irish Republican Army and the Palestine Liberation Organisation.
Libya's involvement in attacks in Europe in the 1980s triggered US military strikes in 1986. Dozens of people were killed, including the Libyan leader's adopted daughter.
However, Colonel Gaddafi returned to the international fold after Libya settled civil claims of victims of the 1988 Lockerbie airliner bombing and agreed to stop developing weapons of mass destruction.
Western politicians, including the British, Italian, French and German leaders, thereupon visited Tripoli in search of lucrative economic deals.
Muammar Gaddafi was born in the desert near Sirte in 1942. He married twice and had eight children, several of whom had roles in the security forces.
Col Gaddafi's eldest son, Seif al-Islam, was initially seen abroad as a moderating and reformist influence, but after the 2011 uprising adopted the image of a hard-line supporter of his father. He is now in Libyan custody.