Only a few Mainers have their histories entwined with the legacy of Margaret Thatcher, Britain’s prime minister for more than 11 years and the first female leader of a major Western country in modern times. George Mitchell, who represented Maine in the U.S. Senate from 1980 to 1995, and soon after helped negotiate peace in Northern Ireland, is one of them.

Thatcher died Monday at the age of 87 and will be remembered as Mitchell described her to the BDN: She was an “outstanding leader” with a “strong personality” who was also an effective speaker and “very decisive in difficult circumstances.” No one must agree with all her political views to hold her in high regard. “I didn’t agree with some of her policies, but I admired her, and we got along quite well,” Mitchell said.

People identified with her working-class roots. She was born in 1925 as the second-oldest child in a family that lived in a flat above the family’s grocery store. Thatcher, then Margaret Hilda Roberts, was ambitious. Starting in 1943 she studied chemistry at the University of Oxford’s Somerville College, where she was elected president of the Oxford University Conservative Organisation.

She learned early how to be tough. In 1950 and 1951, she drew national publicity as the youngest woman candidate in the country when she ran as a Conservative candidate in the general elections — though she lost both times. She married, gave birth to twins, studied to be a lawyer and finally won a seat in Parliament in 1959. She worked her way up and became education secretary in 1970 and leader of Britain’s Conservative Party in 1975.

Thatcher brought her party victory. In the general election of May 1979, Conservatives won a parliamentary majority, and Thatcher became prime minister of the United Kingdom. On May 4, 1979, following her election and having arrived at No. 10 Downing Street, she was asked to share her thoughts.

“I would just like to remember some words of St. Francis of Assisi,” she said. “‘Where there is discord, may we bring harmony. Where there is error, may we bring truth. Where there is doubt, may we bring faith. And where there is despair, may we bring hope.’”

She may have held office longer than any other British politician in the 20th century, but her tenure was not marked by harmony. She started her first of three terms at a time of economic discontent. Income taxes were cut, but sales taxes increased, along with gasoline prices. Unemployment grew, and interest rates soared. There was rioting and looting in the streets.

Little did Thatcher know that when Argentina invaded the Falkland Islands in 1982, the course of events would reverse public opinion and set her reputation. The Soviet media had labeled her the “Iron Lady” after a hard-line speech in 1976, but her unwillingness to negotiate on the islands and to use force when other leaders urged diplomacy cemented her notoriety as a strong-willed commander.

She supported President Ronald Reagan’s defense policies and helped secure the end of the Cold War, for which Maine Sen. Susan Collins expressed her gratitude on Monday. “With principled leadership, and in characteristically bold style, she helped face down the Soviet threat in the Cold War,” Collins said.

With an anti-union and anti-big-government agenda, cuts to welfare programs and an aggressive foreign policy approach, Thatcher, along with Reagan, helped launch modern conservative ideals. She generated many opponents in life — and now in death. On Monday, a former Member of Parliament in the Labour Party, George Galloway, tweeted, “Tramp the dirt down.” People opened champagne to celebrate her death.

Yet both in terms of her economic class and sex, Thatcher broke barriers. “Sociologically, she’s way more progressive than she is in terms of her own policies — as a woman in the lower middle class becoming the head of Britain,” said David Kuchta, a history professor with the University of Southern Maine. Her “tough as nails” attitude has been replicated to a certain degree by former Secretary of State Hillary Clinton and German Chancellor Angela Merkel.

Mitchell described Thatcher as a critical figure in British history who will be remembered in both positive and negative ways by those within her country and around the world. Specifically on the issue of peace in Northern Ireland, for example, there is no doubt she evoked hostility from Ireland and the nationalists in Northern Ireland, but, “You have to put it in context,” Mitchell said.

For decades, there was little cooperation between the governments of Britain and Ireland. But, in 1985, Thatcher, under the Anglo-Irish Agreement, agreed to a framework for regular conferences to allow British and Irish ministers to discuss Northern Ireland issues. It also committed the British government for the first time to promoting legislation for a unified Ireland if a majority favored it.

The agreement was a “steppingstone,” Mitchell said, as it led to the Downing Street Declaration under Prime Minister John Major in 1993 and later the Good Friday Agreement under Prime Minister Tony Blair in 1998. Thatcher, Mitchell said, laid “the foundation that was later built upon.”