Rachel Lomax, 51, who is expected to be named this week as head of the Downing Street policy unit, is one of the most successful women in the history of the Civil Service.
After entering the Treasury at the age of 23 as an economist, she rose through the ranks to become Permanent Private Secretary to Nigel Lawson when he was Chancellor.
She moved briefly to the Cabinet Office in 1994, where she worked with Sir Robin Butler, the head of the Home Civil Service.
Mrs Lomax then spent 18 months at the World Bank in Washington, initially as the bank's troubleshooter for Turkey, Bulgaria and Romania, before becoming chief-of-staff to the incoming president, James Wolfensohn.
She returned to Britain last September to take up the post of Permanent Secretary at the Welsh Office.
The daughter of two teachers, she attended Cheltenham Ladies College before gaining a first in history at Cambridge University and a second degree at the London School of Economics. She is divorced with two sons, one a doctor and the other a disc-jockey.
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