Led by Angela Merkel, Hillary Clinton and Theresa May, there have never been so many experienced and ambitious women in positions of influence, even if they remain heavily outnumbered.

Clinton has already made history by becoming the first female presidential nominee of a major US political party in her bid for the White House in November.

"This is historic, just as Barack Obama was historic. There is no question about that," said Ester R. Fuchs, professor of public affairs and political science at Columbia University, referring to the first black US president.