Elected MP for Orkney and Shetland in 2001, Alistair Carmichael swiftly became a Northern Ireland spokesman.
The 40-year-old stayed with that brief until 2005 when he joined the Lib Dems' home affairs team.
Following Sir Menzies Campbell's election as leader the married father of two has been promoted to shadow the secretary of state for transport.
Before being elected to Parliament Mr Carmichael was a solicitor and also a hotel manager.
As an MP he has sat on the Scottish Affairs select committee and been a member of all-party groups including ones on fishing, offshore oil and has and telecommunications.