Jose Luis Rodríguez Zapatero has been sworn as Spain's new prime minister. For the first time, women make up half of the new Spanish Cabinet.

Spain's King Juan Carlos officiated Saturday over the swearing-in of his fifth prime minister since the restoration of democracy 25 years ago. In a brief ceremony in the royal residence of Zarzuela Palace, the 43-year-old Mr. Zapatero placed his right hand on a copy of the Spanish constitution - rather than a Bible - and swore to uphold its provisions.

Mr. Zapatero was elected to parliament as a socialist candidate from his hometown of Leon at age 26, making him the youngest member of the legislature. In the year 2000, after the second victory of the center-right Popular Party, headed by Jose María Aznar, Mr. Zapatero became Socialist Party leader.

The new prime minister's first public act was to place a bouquet of flowers at an improvised shrine of candles and placards set up at the Atoca station for the 191 people killed in the terrorist bombings of four commuter trains on March 11. He then visited injured attack victims still in the hospital.

Mr. Zapatero, described by his friends as affable and open to dialogue, won a surprise victory in the general elections of March 14 over the Popular Party. Polls had favored the PP by a narrow margin, because of eight years of generally good economic administration. But swing voters reacted to the tragedy of the terrorist attacks and the government's attempt to pin the blame on the Basque terrorist group, ETA. They gave the Socialists nearly 43 percent of the vote. The PP got 38 percent.

Another factor was the war in Iraq. Mr. Zapatero had been a relentless critic of Mr. Aznar's steadfast support of President Bush' invasion of Iraq. More than 80 percent of Spaniards were against the campaign. When he won the election, Mr. Zapatero promised to withdraw the 1,300 Spanish troops from Iraq, unless the United Nations takes charge there by June 30.