Lord Russell-Johnston became the MP for Inverness in 1964
Former Scottish Liberal leader Lord Russell-Johnston has died in Paris at the age of 75.
Lord Russell-Johnston, who had been diagnosed with cancer, was an MP for Inverness for 33 years until 1997.
He was also a Scottish Liberal Democrat deputy leader and member of the Council of Europe's Parliamentary Assembly.
Liberal Democrat leader Nick Clegg described Lord Russell-Johnston as "an institution in his own right". The peer leaves a wife and three sons.
Mr Clegg said: "He will be sorely missed not only by friends, family and colleagues in the UK but by all those countless people whose lives he touched throughout Europe.
"My thoughts are with his wife Joan and his three sons and the rest of Russell's family at this difficult time."
He was the MP for the Liberals then the Liberal Democrats for Inverness from 1964 to 1983 and the seat of Inverness, Nairn and Lochaber from 1983 to 1997.
Lord Russell-Johnston was knighted in 1985 and made a life peer in 1997 as Baron Russell-Johnston of Minginish in Highland.
He changed his name by deed poll to incorporate his Christian name in the title.
Fellow Scottish Liberal Democrat, former party leader Sir Menzies Campbell, said: "Russell Johnston was a Liberal in thought, word and deed.
"He was pro-European and pro-Home Rule when these enthusiasms were not fashionable. Scottish and European politics have lost a man of integrity and wisdom."
Acting Scottish Liberal Democrat leader Michael Moore said Lord Russell-Johnston was "one of the giants of Scottish Liberalism in the last quarter century".