International Development Secretary Baroness Amos has been appointed leader of the House of Lords.
Baroness Amos: New Lords leader
The move comes in a mini-reshuffle forced by the sudden death of previous Lords leader Lord Williams of Mostyn.
Also promoted, to take over as international development secretary, is Hilary Benn, whose father Tony is a previous Labour cabinet minister.
Baroness Amos became the first black woman to sit in the cabinet when she replaced Clare Short, who quit her post after the military action in Iraq earlier this year.
Previously she had been a foreign office minister.
Mr Benn was already tipped as a rising star on the Labour benches before this promotion.
His first government appointment came just two years after he became an MP in a by-election.
He has described himself as a Benn but not a Bennite.
Trial by jury
Lady Amos takes on her new job at a difficult time for the upper house which has yet to undergo its next stage of reform.
Peers are also in the process of considering two of the government's most controversial pieces of legislation - restricting the right to trial by jury and plans for foundation hospitals.
Hilary: A Benn, not a Bennite
Baroness Amos was Parliamentary Under-Secretary of State, Foreign and Commonwealth Office for two years before joining the cabinet.
Previously she was a Government Whip from 1998 to 2001 and a co-opted member, European Union Sub-committee F (Social Affairs, Education and Home Affairs) from 1997-98.
Born in March 1954 in Guyana, Valerie Ann Amos began her career in local government, working in various London boroughs from 1981 to 1989.
She was educated at Townley Grammar School for Girls before completing a degree in sociology at Warwick University in 1976, a masters degree in cultural studies from Birmingham University in 1977 and doctoral research at University of East Anglia.
She was chief executive of the Equal Opportunities Commission from 1989 to 1994, and then director of Amos Fraser Bernard from 1995 to 1998.
She became a life peer in 1997, taking the title Baroness Amos, of Brondesbury in the London Borough of Brent.
She was deputy chair of the Runnymede Trust, a trustee of the Institute of Public Policy Research and involved in Project Hope, an organisation which promotes healthcare.
Her charity works involved being the chair of the board of governors at Royal College of Nursing Institute from 1994 to 1998 and one of the directors of Hampstead Theatre.