Angus Robertson is one of the most senior figures at the heart of the SNP machine.
He was brought up in Edinburgh and after studying politics and international relations at Aberdeen University, he embarked on a career in journalism, working as a foreign and diplomatic correspondent in central Europe for the BBC and Austrian radio.
The 41-year-old was an adviser to the SNP at Holyrood before winning election to Westminster in 2001. He is a close ally of Alex Salmond, who put him in charge of the party's Scottish election campaign in 2007, which resulted in a narrow but historic victory.
It meant Mr Salmond went back to Holyrood as First Minister, with Mr Robertson succeeding him as leader of the SNP group at Westminster.
His finest moment was heading the SNP election triumph last month as the SNP surged to an unprecedented majority.