Protected by an umbrella as heavy rain fell, the world's richest man walked into one of SA's most desperately impoverished townships on Friday.

Bill Gates, founder of Microsoft, and his wife Melinda visited the Inkanini Primary School in Khayelitsha.

It was not immediately clear what brought the family to Site B in Khayelitsha but their foundation has done significant work previously in the country.

The Bill and Melinda Gates Foundation serves several interests in SA, including HIV/Aids prevention programmes that began in 1999, water and sanitation and agriculture.

“SA is a country with global influence that has both significant challenges, including high rates of HIV and TB, and critical assets, such as a world-renowned scientific and research community,” according to the foundation's website.

“Since making our first grants here in 1999, we have been committed to addressing these issues and investing in its promising future.

“We are working with SA to apply its clout, research, and solutions to address its greatest needs.”

On Friday, The Economic Times reported that Gates had just reclaimed his title as the world's richest man after Amazon founder and CEO Jeff Bezos saw his shares fall 7%.

Bezos is now worth an estimated $103.9bn (R1.52-trillion) and Gates $105.7bn (R1.54-trillion).