Answer by taking a quote from the following article:

Robin Cook was born in the County Hospital, Bellshill, Scotland, the only son of Peter and Christina Cook (nee Lynch). His father was a Chemistry teacher who grew up in Fraserburgh, and his grandfather was a miner before being blacklisted for being involved in a strike. Cook was educated at Aberdeen Grammar School and, from 1960, the Royal High School in Edinburgh. At first, Cook intended to become a Church of Scotland minister, but lost his faith as he discovered politics.

After his 2003 resignation from the Cabinet, Cook remained an active backbench Member of Parliament until his death. After leaving the Government, Cook was a leading analyst of the decision to go to war in Iraq, giving evidence to the Foreign Affairs Select Committee which was later relevant during the Hutton and Butler inquiries. He was sceptical of the proposals contained in the Government's Higher Education Bill, and abstained on its Second Reading. He also took strong positions in favour of both the proposed European Constitution, and the reform of the House of Lords to create a majority-elected second chamber, about which he said (while he was Leader of the Commons), "I do not see how [the House of Lords] can be a democratic second Chamber if it is also an election-free zone".  In the years after his exit from the Foreign Office, and particularly following his resignation from the Cabinet, Cook made up with Gordon Brown after decades of personal animosity -- an unlikely reconciliation after a mediation attempt by Frank Dobson in the early 1990s had seen Dobson conclude (to John Smith) "You're right. They hate each other." Cook and Brown focused on their common political ground, discussing how to firmly entrench progressive politics after the exit of Tony Blair. Chris Smith said in 2005 that in recent years Cook had been setting out a vision of "libertarian, democratic socialism that was beginning to break the sometimes sterile boundaries of 'old' and 'New' Labour labels". With Blair's popularity waning, Cook campaigned vigorously in the run-up to the 2005 general election to persuade Labour doubters to remain with the party.  In a column for the Guardian four weeks before his death, Cook caused a stir when he described Al-Qaeda as a product of a western intelligence:  Bin Laden was, though, a product of a monumental miscalculation by Western security agencies. Throughout the 80s he was armed by the CIA and funded by the Saudis to wage jihad against the Russian occupation of Afghanistan. Al-Qaeda, literally "the database", was originally the computer file of the thousands of mujahideen who were recruited and trained with help from the CIA to defeat the Russians.  Some commentators and senior politicians said that Cook seemed destined for a senior Cabinet post under a Brown premiership.

Did he work anywhere else besides Parliament?
In the years after his exit from the Foreign Office, and particularly following his resignation from the Cabinet, Cook made up with Gordon Brown after decades of personal animosity --