Time magazine has named Bill and Melinda Gates, and rock star Bono, as its 'Persons of the Year' citing their charitable work and activism aimed at reducing global poverty and improving world health.

The reason for the award is hard to miss. The Microsoft chairman and his wife have built the world's largest charity, the Bill and Melinda Gates Foundation.

It has a $29bn endowment and has been giving away money faster than any other charity in history.

The Foundation is credited with saving at least 700,000 people by investing in vaccination programmes, and has donated computers and internet access to 11,000 libraries. It has also sponsored the biggest scholarship fund in history.

Jim Kelly, managing editor at Time, said: "Natural disasters are terrible things, but there is a different kind of ongoing calamity in poverty, and nobody is doing a better job in addressing it in different ways than Bill and Melinda Gates and Bono."

Time also named former presidents Bill Clinton and George H. W. Bush as 'Partners of the Year' for their work on behalf of the victims of the tsunami and hurricane Katrina.