The present-day Liberal Democrat Party, which was formed when the Liberal and Social Democratic Parties merged in 1988, is the third largest party in Britain in terms of electoral results, with 63 Members of Parliament.
As well as great success at a local level in England, the Liberal Democrats have gained many seats in Scotland and, consequently, help make up a coalition leadership with Labour in the Scottish Parliament.
The party's ideology is based around a commitment to the welfare state, social equality, environmental protection and an aversion to excessive government intervention, but with less emphasis on economic liberalism than foreign liberal parties.
The Liberal Democrats' present leader, Menzies Campbell, was elected to the role after an eventful and sometimes controversial leadership contest in which two front-running candidates had to withdraw due to sexual scandals.
The leadership contest itself was brought about when the former leader - Charles Kennedy, who had been one of the party's most popular and successful leaders - was ousted by party members due to his alcoholism.
One policy that both Campbell and Kennedy have pursued with vigour is that of the Liberal Democrat's opposition to the Iraq War - they are the only major party to consistently take this line. The party has also developed environmental policies to penalise polluters, and propose tax increases for society's highest earners.