Bildt, 57, has thus taken the unusual decision to return to government and serve in a lower post to the one he previously held: that of prime minister.
He led the Scandinavian nation from 1991 to 1994 at the head of a centre-right coalition which, like the administration he is now joining, had brought to an end an extended period of Social Democratic rule.
Bildt, who has strongly pro-European Union views, also spent a year and a half as the EU’s high representative to Bosnia-Hercegovina, during the period when the Balkan nation was emerging from the horrors of war.
Carl Bildt was born on July 15, 1949 in the southern town of Halmstad. Studying politics at Stockholm University, he became an acknowledged specialist in both defence and foreign policy.
He was elected to parliament for the conservative Moderate Party, which he went on to lead.
In 1991 he became one of the country’s youngest ever prime ministers, at the age of 42.
The pro-free market policies he sought to bring in – in a country renowned for its welfare state and long tradition of rule by Social Democrats – were frustrated by a severe financial crisis.
Between the end of his administration in 1994 and Reinfeldt’s election victory this year, the Social Democrats again ruled the roost in Sweden.
His term as premier ended, Bildt was made the international community’s first envoy in Bosnia in January 1996, two months after the agreement which determined the shattered nation’s post-war status.
He was to hold that job, which required a firm hand in dealing with Bosnia’s complex politics, until June the next year, when he handed over to Carlos Westendorp of Spain.
While in Bosnia, Bildt was also to meet and fall in love with an Italian diplomat, a development which kept the gossip columnists busy back home in Sweden. He and his first wife Mia, with whom he has two children, were divorced in 1996.
After his return to Sweden from the Balkans, the straight-talking Bildt was accused of downplaying his local constituents’ concerns, preferring to emphasise the harsh conditions in the former Yugoslavia.
In 1999, he returned to the Balkans to serve as the special envoy of the United Nations secretary general, and served in that capacity until 2001.
A man of considerable energy and youthful good looks, Bildt is often cited as one of Sweden’s most popular politicians. He maintains a personal web site at www.bildt.net.
He serves on the board of trustees of US think tank RAND Corporation and as non-executive director of Vostok Nafta, a Swedish investment company for the Russian oil and gas industry.