Simeon Saxe-Coburg-Gotha, the last Tsar of Bulgaria when he was a child, is sworn in as Prime Minister of Bulgaria, becoming the first monarch in history to regain political power through democratic election to a different office.

Simeon Borisov von Saxe-Coburg-Gotha (Bulgarian: Симеон Борисов Сакскобургготски, romanized: Simeon Borisov Sakskoburggotski, [simeˈɔn boˈrisof sakskoburˈgɔtski]; born 16 June 1937) is a Bulgarian politician who reigned as the last tsar of the Kingdom of Bulgaria as Simeon II from 1943 until 1946. He was six years old when his father Boris III of Bulgaria died in 1943 and royal power was exercised on his behalf by a regency led by Simeon's uncle Kiril, Prince of Preslav, General Nikola Mihov and prime minister, Bogdan Filov. In 1946 the monarchy was abolished by referendum, and Simeon was forced into exile.

He returned to his home country in 1996, formed the political party National Movement Simeon II (NMSP) and was elected Prime Minister of the Republic of Bulgaria from July 2001 until August 2005. In the next elections, as a leader of NMSP, he took part in a coalition government with the Bulgarian Socialist Party. In 2009, after NMSP failed to win any seats in Parliament, he left politics.

On 24 July 2001, he gave his official oath in the name of Republic of Bulgaria to serve as Prime Minister.