Steinmeier, a Social Democrat, took over from party colleague Franz Müntefering, who resigned last week to take care of his wife in her battle against cancer.

The 51-year-old has served as Germany's foreign minister since November 2005, but his tenure in that office has remained low-key. That's partly due to the popularity of his predecessor, the Green party's Joschka Fischer, and to the tendency of conservative Chancellor Angela Merkel to take center stage at foreign policy events.

A trained lawyer, Steinmeier has a reputation as a political pragmatist capable of mediating between differing views. He was also considered the closest advisor to Gerhard Schröder, Merkel's Social Democratic predecessor, and a major architect of Schröder's stance against the US-led war in Iraq.

Criticism of past activities

Steinmeier has, however, come under fire in conjunction with his post as chief-of-staff of the Federal Chancellery under Schröder, a position he held from 1999 to 2005.

In particular, Steinmeier has been criticized for his handling of the case of Murat Kurnaz, a Turkish man born and residing in Germany who the US imprisoned without proof of any wrongdoing for five years at the Guantanamo Bay prison camp in Cuba.

Critics say Steinmeier refused an offer by the United States in 2002 to release Kurnaz. Earlier this year, Steinmeier was called to testify in front of a parliamentary investigative committee about the case and said he had no knowledge of the offer in question.

On a lighter side, Steinmeier recently raised smiles when he teamed up with his French foreign ministerial counterpart to record an ill-conceived rhythm-and-blues song in Berlin.

No real increase in power

The duties of the vice chancellor are largely ceremonial, consisting mainly of deputizing at functions the chancellor is not able to attend. In contrast to the vice president of the United States, the vice chancellor does not inherit the chancellorship, should a chancellor die in office.

Still, Steinmeier's assumption of the new position, in addition to his serving as Germany's foreign minister, can only bolster his public profile and solidify his role within the grand coalition.

The job of labor minister -- the other position vacated by Müntefering -- has been given to Social Democrat Olaf Scholz.