Kennedy had served as an MP for 32 years, joining the House of Commons as its youngest MP in 1983.
Kennedy's career was one of highs and lows, from leading the Lib Dems to their greatest ever election victory and speaking passionately against the Iraq war in 2003, to admitting his personal struggle with alcohol, and losing his seat after three decades in this year's election as the SNP swept the board north of the border.
HuffPost UK political director Paul Waugh writes: "The phrase 'a man of principle' can become hackneyed, but for Charles it was all too true. His courage in leading his party against the Iraq war, a move that helped the Lib Dems to their biggest share of seats, was much praised. His decision to vote against the formation of the Coalition in 2010 - the only MP in his party to do so - again underlined how he refused to compromise his beliefs."