The children of former British Prime Minister Margaret Thatcher donated personal documents of some of the most important moments of her mandate to a foundation based at the University of Cambridge to reduce inheritance taxes, according to the Daily Telegraph newspaper.

The newspaper noted on that the “Iron Lady’s” estate is valued at 4.7 million sterling pounds (about $7.4 million), of which 1.8 million pounds (roughly $2.8 million) should be paid in taxes.

The donation of the documents, valued at 1 million pounds (some $1.5 million), will allow Mark and Carol Thatcher, the children of the former prime minister who died in 2013, to reduce taxes payable by half.

“The family was offered a larger sum by an American university for the papers, meaning they have turned down a potential windfall in order to keep the papers in Britain,” Daily Telegraph reported.

“The bundle of personal papers, which are understood to include ‘four or five’ hand-written accounts of the former prime minister’s reflections on some of the key events of her 11-year premiership, have been donated to the Margaret Thatcher Foundation, based at Churchill College, which will publish them on its website,” the newspaper added.

Thatcher, who served three consecutive terms as head government from 1979-1990, bequeathed one-third of her estate to her son Mark, 61, the same amount to his twin sister Carol, and the remaining third was put into a trust fund for her grandchildren Michael, 25, and Amanda, 20.