Her Conservative government, from 1979 to 1990, privatised several state-owned industries, was involved in trade union stand-offs and fought a war for the Falkland Islands. Baroness Thatcher was a key mover behind the fall of communism in eastern Europe.
Sir John Nott, Conservative MP for St Ives from 1966 to 1983, who served in Baroness Thatcher's first Cabinet, told the Western Morning News: "In my view she was a very great lady. There is no doubt about it – she will be remembered as the greatest peace-time Prime Minister. And alongside Ronald Reagan, they ended the Cold War.
"She got what she wanted to get in the face of a great deal of opposition, even from her own Cabinet. The economic situation was extremely difficult in 1979, even more so than it is now. Inflation was in double figures. Three million unemployed. She turned the country around."
Sir Gerry Neale, Conservative MP for North Cornwall between 1979 and 1993, said her political legacy stretched beyond restoring the Conservative Party's fortunes, and had a "profound effect" on shaping Labour following three general election victories.
Sir Gerry said: "She had a remarkable impact on my life and politics. The state of the country in 1979 after the winter of discontent needed a huge amount of courage to confront. And she stepped up to the mark every time."
Devon business leader Neill Mitchell was a Downing Street civil servant in Baroness Thatcher's private office in the early 1980s, and said she had a caring, housewife's manner almost to the point of "1950s stereotype".
He said she played a pivotal role in ending the Cold War and dismissed those who suggested she destroyed society.
Mr Mitchell said: "The country was being held ransom by one union after another. Holding the country to ransom is not society. Unions weren't contributing to society cohesion."
Former Plymouth MP Lord David Owen, who was a former Labour Foreign Secretary and founder member of the breakaway SDP party in the early 1980s, said Baroness Thatcher had been "a formidable figure who had changed our country". He went on: "At times she could be very insensitive. With her, you were dealing with a person with a very considerable intellect."
Former Liberal Democrat leader Lord Paddy Ashdown, the ex-MP for Yeovil, said he "opposed her in most of the things she did" and added that she was a "better destroyer than a builder".
But he added: "These were things that needed to be done if Britain was to be dragged into the 20th century."
Former Conservative Deputy Prime Minister Lord Heseltine, MP for Tavistock between 1966 and 1974, issued a statement which said: "I am sorry to learn of Lady Thatcher's death. The illness of her last years has been cruel and very difficult. I send my deepest condolences to Mark and Carol."
Serving Conservative MPs from the Westcountry also paid tribute.
Foreign Office Minister Hugo Swire, Conservative MP for East Devon, said: "She was an extraordinary individual, both in terms of being the first woman Prime Minister against the odds and how she turned this country back from the dark days of the 1970s.
"History will judge her as one of the greatest Prime Ministers this country has ever seen."
George Eustice, Conservative MP for Camborne and Redruth, said: "Margaret Thatcher took the reins at a desperate time for Britain when strong leadership was required.
"She played a central role in turning the country around, challenged the resignation to post-war British decline and also contributed to the end of the Cold War.
"While some of her policies were contentious at the time, she will ultimately be remembered, not only as Britain's first woman Prime Minister, but as a great leader."
Totnes Conservative MP Sarah Wollaston said Baroness Thatcher was an "exceptional woman and great Briton", adding: "We should be proud of our Iron Lady."
Former minister Gary Streeter, Conservative MP for South West Devon, said: "We have to take our minds back to 1979 when she came to power. Britain was the sick man of Europe.
"Over ten years she put in place the foundations for a strong economy, sorted out the trade unions, enabled a lot of people to buy their own houses, and to buy shares for the first time.
"She transformed the political landscape."
Neil Parish, MP for Tiverton and Honiton, said: "There can be no doubt that she was one of the greatest Prime Ministers this country has ever seen and her passing marks the end of a life spent in service to her country."
Ashley Fox, Conservative MEP for the South West, said: "She is my political hero and one of the greatest leaders of the 20th century. She brought Britain back from the brink of bankruptcy, helped win the Cold War and once again assured our country a leading role in global politics."
Maragret Thatcher: In the words of others "She is the best man in England."– Ronald Reagan, 1983 "Mrs Thatcher is doing for monetarism what the Boston Strangler did for door-to-door salesmen."– ex-Labour Chancellor Denis Healey, 1977 "Attila the Hen."– Former Liberal MP Sir Clement Freud, 1979 "She is clearly the best man among them."– Barbara Castle referring, in her diaries, to the Tory front bench "She has no imagination, and that means no compassion."– ex-Labour leader and Plymouth MP Michael Foot, 1982 "Politicians are either warriors or healers. Margaret Thatcher is a healer."– Patrick Cosgrave in his biography of ThatcherMaragret Thatcher: In her own words "I wasn't lucky. I deserved it."– Comment on receiving a school prize, aged nine "I am not hard – I'm frightfully soft. But I will not be hounded."– Interview, 1972 "I've got a woman's ability to stick to a job and get on with it when everyone else walks off and leaves it."– Speech, 1975 "Britain is no longer in the politics of the pendulum, but of the ratchet."– Speech to the Institute of Public Relations, 1977 "To those waiting with bated breath for that favourite media catchphrase, the U-turn, I have only one thing to say: You turn if you want to. The lady's not for turning."–Speech at Conservative Party conference, 1980 "We knew what we had to do and we went about it and did it. Great Britain is great again."– Comment at end of Falklands conflict "This is a day I was not meant to see."– The Sunday following the Brighton bomb "I fight on. I fight to win."– Statement on November 21, 1990, after she was forced into a second ballot in the leadership battle, but she in fact withdrew before it occurred "Having consulted widely among colleagues, I have concluded that the unity of the party and the prospects of victory in a general election would be better served if I stood down to enable Cabinet colleagues to enter the ballot for the leadership."