a former British political party. It developed in the mid 19th century from the Whigs, and under William Gladstone and David Lloyd George became the party of social and political reform. It lost support after the rise of the Labour Party in the early 20th century. In the elections of 1983 and 1987 the Liberals achieved some success by joining with the Social Democratic Party to form the Alliance, and the two parties were officially united in 1988. They were then called the Liberal Democratic Party.