Politicians have often been compared to former British Prime Minister Margaret Thatcher.
A few years ago, it was Hillary Clinton who suggested a similarity.
"I spoke to her (Thatcher) about Hillary Clinton a few years ago, when Mrs. Clinton likened herself to Margaret Thatcher," said Andrew Roberts.
As a historian and the trustee to the Archives of Margaret Thatcher, Roberts asked the prime minister what she thought of the comparison.
"It would have been very easy for Margaret Thatcher to accept what was clearly intended to be a compliment and instead she didn't. She was far too instinctively honest a politician," explained Roberts. "She said, 'she's not the least like me, and I know that because I'm not the least like her.'"
Of course, rather than the comparison of two women in leadership roles, she was talking about their differing politics.
According to Roberts, Thatcher never made much of herself being a woman - with the exception of a few avian analogies.
"She would have a few jokes about how the men do the clucking, but the ladies lay the eggs," said Roberts. "But she didn't ever, ever, think that she should be prime minister because she was a woman. She was a prime minister who happened to be a woman."