The recipe for a powerful woman: Live in the US, work in business and go into politics

Although the top four places are awarded to government officials, it appears that the corporate ladder is the most rewarding career in the power stakes; the list includes 13 company chairwomen and 13 chief executives. Other labels include president (five), prime minister (four), Nobel Laureate (two) and queen (two).

Ms Rice recalls from her childhood in racially segregated Alabama: "My parents had convinced me that you may not be able to have a hamburger at Woolworth's but you can be President of the United States." At the age of 50, the first African-American Secretary of State now stands as a future presidential contender, although she has denied having such ambitions. The hawkish official has the ear of President George Bush, and is top of the most complete survey of the women in the world who count, from Singapore to San Francisco.

Senator Hillary Clinton, a Democratic contender for president who was number five on last year's list, is ranked 26th this year. Laura Bush, First Lady who was number four last year, is now back in 46th place.

China's Wu Yi makes a return appearance in second place. The 66-year-old Vice-Premier and Health Minister, who worked her way up the ranks of the state oil company, has made a success of her career in an industry dominated by men.

Julia Tymoshenko, Ukraine's new Prime Minister, jumps in at third place. She was rewarded with the post for her loyal support of Viktor Yushchenko during the former Soviet state's orange revolution last year.

Gloria Arroyo, the embattled president of the Philippines, comes fourth. She also made the top 10 last year. But Sonia Gandhi, the Italian-born widow of Indian prime minister Rajiv Gandhi and leader of India's ruling Congress party, who was third on last year's list, has vanished from 2005's top 100.

The top businesswoman is the eBay chief executive, Margaret Whitman, in fifth place.

Britain's first entry, Marjorie Scardino, at number 18, is the chief executive of Pearson, the parent company of the Financial Times Group and Penguin publishing, which grossed $7.2bn last year. Other British entries include the Harry Potter author J K Rowling at 40, Cherie Blair at 62 and the Queen at 75.