He served as Bulgaria's prime minister from 2001 to 2005, which makes him one of the only two former monarchs, who have become heads of government through democratic elections.

[5] The Bulgarian director Andrey Paounov dedicated a documentary titled The Boy Who Was a King, covering the returning of Simeon II to Bulgaria, his election as prime minister and his years in government.

This branch was founded by Prince August's youngest son Ferdinand, who was elected as monarch of Bulgaria in 1887.

Princess Maria Antonia Koháry inherited over 150000 hectares of land in Lower Austria, Hungary, including estates, forests, mines and factories.

According to a list of assets appended to the marriage contract of her son, Prince August, at the time of his marriage to Princess Clémentine in 1843, the Koháry properties included the enormous Palais Koháry in the center of Vienna and several Viennese manors, a summer home and lands at Ebenthal, Lower Austria, estates in Austria at Velm, Durnkrut, Walterskirchen, Bohmischdrut and Althoflein, as well as a dozen manors in Hungary, the domain of Királytia, and a mansion at Pest.

In 1851, a committee headed by Prince August of Saxe-Coburg and Gotha set out to plan the construction of a Catholic church in Coburg with a burial vault underneath.