Barroso served as president of the European Commission from 2004 to 2014, and as Prime Minister of Portugal from 2002 to 2004. He was first elected to the Portuguese Parliament in 1985, and then served as state secretary for home affairs, state secretary for foreign affairs and cooperation, and minister for foreign affairs in successive governments.
Barroso will chair Goldman Sachs International (GSI), which is headquartered in London and has around 5,000 staff based in Britain, with almost 1,000 based overseas. He will also act as an adviser to Goldman Sachs.
"His perspective, judgment and counsel will add great value to our GSI Board of Directors, Goldman Sachs, our shareholders and our people," the company said in a statement today.
Goldman Sachs was firmly behind a Remain vote in the recent EU referendum - the US bank was believed to have pledged £500,000 to the In campaign.