William Gladstone was described by his rival Benjamin Disraeli as an "unprincipled maniac". Gladstone said "Dizzy" was a destroyer of principles.

Trotsky fought a losing battle with Stalin to lead the Soviet Union after Lenin's death.

Boris Yeltsin was initially under Mikhail Gorbachev's wing in the Communist Party, then struck out on his own..

The rivalry between Khaleda Zia and Sheikh Hasina has dominated Bangladeshi politics for years.

Conservative leader Jacques Chirac spent an uncomfortable spell as French PM under his Socialist foe, the late Francois Mitterrand, before succeeding him as president.

Bill Clinton was harried at every turn by Speaker of the House Newt Gingrich after the Republicans' landmark 1994 congressional victory.