Baroness Margaret Thatcher, the longest-serving Prime Minister of the United Kingdom in the 20th century, and the first and only female prime minister, has died of a stroke at age 87.

Thatcher was among the best-known foreign politicians in the U.S., likely because of her close working relationship with Ronald Reagan, with whom she shared a reactionary worldview and utter lack of compassion. She was also similarly transformative: In the 11 years of her premiership, between 1979 and 1990, Thatcher sold off billions of pounds worth of government assets—privatizing even industries for which no real competitive market existed—used an unnecessary and avoidable war against Argentina to manufacture enough jingoistic sentiment to earn her re-election, and broke the power of British trade unions, calling the miners who participated in a 1984 strike directed against her politics "the enemy within." Modern Britons are still living within the social, political and economic structures she built, and suffering from the absence of the structures she disabled. Millions of people in England, Scotland, Ireland and Wales (and in South Africa and Cambodia and Chile) will be celebrating tonight. (To be fair! Many will be mourning.) (Also celebrating: gay people!)

On the other hand, she helped invent soft-serve ice cream.

[image, of Margaret Thatcher and Jimmy Savile, a powerful radio DJ, via Getty]

Note: an earlier version of this obituary wrote that Margaret Thatcher "manufactured" the war in Argentina. While we stand by the general sentiment, the wording has been changed to more specifically reflect her role.