Condoling the death of Britain's first woman prime minister Margaret Thatcher, Prime Minister Manmohan Singh said she was a "transformative figure" under whom Britain registered important progress on the national and international arena. "I express my deepest sadness on the passing away of former British prime minister Baroness Margaret Thatcher," Manmohan Singh said in his message. Britain's first woman Prime Minister Margaret Thatcher, known as the Iron Lady, on Monday passed away following a stroke at the age of 87. "It is with great sadness that Mark and Carol Thatcher announced that their mother Baroness Thatcher died peacefully following a stroke this morning", Lord Bell, her spokesperson said. Thatcher was Conservative Prime Minister from 1979 to 1990. "She was a transformative figure under whom the United Kingdom registered important progress on the national and international arena," PM Manmohan said. Thatcher, born as Margaret Roberts, became the Conservative MP for Finchley, north London in 1959, retiring from the Commons in 1992. Having been education secretary, she successfully challenged former prime minister Edward Heath for her party's leadership in 1975. "People of India join me in sending our sincerest condolences to the Thatcher family, the government and people of the United Kingdom," PM added. External Affairs Minister Salman Khurshid described Thatcher as a "remarkable, remarkable person, a great leader, powerful leader" and "she will be mourned." "The knowledge she is no longer there is heart breaking and sad, and I would like to convey my condolence to her family and friends," he added. Thatcher won general elections in 1979, 1983 and 1987. Thatcher's government privatised several state-owned industries. She was also in power when the UK went to war with Argentina over the Falkland Islands in 1982. Source: News Bullet