Throughout its 240-year history, the United States has been ruled by men. Hillary Clinton hopes to change that - but other countries got there first.

In 1887 the first woman was elected mayor of an American town, 33 years before women gained the right to vote in the US overall.

Since then 56 women have been elected to the top job in 44 different countries. The US is still waiting.

Katty Kay takes a look at some of those women over the years.

Produced by Franz Strasser