Roelof Botha, the grandson of former South African foreign affairs minister Pik Botha, was closely involved in the funding of social networking site Tumblr, which Yahoo this week agreed to buy for US$1,1bn.

Pretoria-born Botha, who served on Tumblr’s board of directors, was also a key role player in the $1,5bn, 2002 sale of e-commerce company PayPal, where he was chief financial officer.

As a partner of venture capital firm Sequoia Capital, which has provided funding over the years for household names such as Cisco, Oracle, Electronic Arts, Apple, Yahoo and Nvidia, Botha was also involved in the $1,6bn sale in 2006 of video platform YouTube to Google.

YouTube was founded by three of his former PayPal colleagues, Chad Hurley, Steven Chen and Jawed Karim.

Sequoia Capital was also a big shareholder in the New York-based Tumblr, and was involved in providing $30m of funding in 2010 that valued the start-up at about $140m. A year later, its valuation had shot up to $800m.

On Monday, Botha tweeted his congratulations to Tumblr founder David Karp, saying he was the inspiration for this blog post following their first meeting.

Botha, an avid supporter of the Blue Bulls rugby team, who grew up in Hout Bay and who matriculated with straight As, relocated to Silicon Valley in 1998, where he enrolled for an MBA at Stanford University. Before he’d graduated, he’d been appointed as PayPal’s director of corporate development, he told the Financial Mail in a 2007 interview.

As chief financial officer, he oversaw PayPal’s Nasdaq listing in 2002. He was 28 at the time. eBay bought the company five months later.