Maria was born on 6 January 1900, at Friedenstein Palace in Gotha, a town in Thuringia, in the German Empire.

[3] She was named after her maternal grandmother, Grand Duchess Maria Alexandrovna of Russia, and was known as Mignon in the family to distinguish her from her mother.

Since the new Royal Residence in Belgrade was not finished, the king and queen continued to live at the Karađorđević estate.

The simple life of Maria gave her a great deal of favourable publicity, and her popularity also benefitted Alexander, when she and sometimes the sons accompanied him on his trips around Yugoslavia.

She spoke several languages fluently and enjoyed painting and sculpting under the guidance of artist Iva Despić-Simonović.

The regent gave Maria an allowance of six million dinars for herself and her sons: she kept a quarter of the amount, and spend the rest on charity.

It was rumoured at the time that Maria left Yugoslavia because of a conflict with the Prince Regent Paul, but the official reason stated for her move was her health.

On 6 April, Nazi Germany attacked Yugoslavia, and Peter II fled to Britain, arriving in June.

Maria suggested that she should return to Yugoslavia to stand by the Yugoslav people during the war, but was prevented by her health problems from doing so.

Maria herself bought a new farm in Kent, where she lived a simple life with her two younger sons, often seen working in the fields.

Her funeral was held on 2 July 1961 at the Serbian Orthodox Church, Notting Hill, London and was initially interred at the Royal Burial Ground at Frogmore, which adjoins Windsor Castle.