BAKU, Azerbaijan -- Azerbaijan's president on Tuesday appointed his wife as the first vice-president of the ex-Soviet nation -- the person next in line in the nation's power hierarchy.

Ilham Aliyev, 55 named his wife Mehriban, 52, to the position created after a constitutional referendum in September. Mehriban, who married her husband when she was 19, graduated from a medical university. She has served previously as a lawmaker and headed a charity.

The constitutional amendments approved at the referendum introduced the positions of two vice-presidents, one of them the first vice-president.

The first vice-president takes over the presidency if the president is unable to perform his or her duties. It doesn't describe the first vice-president's duties, but it's expected that they will include overseeing the Cabinet.

Aliyev's critics say the September referendum that also extended the presidential term from five to seven years effectively cemented a dynastic rule. In 2003, Aliyev succeeded his father, who had ruled Azerbaijan first as the Communist Party boss and then as a post-Soviet president for the greater part of three decades.

Aliyev and his wife have two daughters and a son.

Aliyev has firmly allied the energy-rich Shiite Muslim nation with the West, helping secure his country's energy and security interests and offset Russia's influence in the strategic Caspian Sea region. At the same time, his government has long faced criticism in the West for alleged human rights abuses and suppression of dissent.

Azerbaijan's leader has cast himself as a guarantor of stability, an image that has a wide appeal in the country where painful memories are still fresh of the turmoil that accompanied the 1991 breakup of the Soviet Union.