Prince Michael III married Countess Julia Hunyady de Kethehy. While in exile, he learned to speak French and German fluently.
https://en.wikipedia.org/...ki/Mihailo_Obrenovi%C4%87"...He married Countess Júlia Hunyady de Kéthely (August 26, 1831 – February 19, 1919), the daughter of Count Ferenc Hunyady de Kéthely and Countess Júlia Zichy de Zich and Vásonkeő. The marriage was childless, although he had at least one illegitimate child by a mistress whose identity is unknown. While in exile, he learned to speak French and German fluently..."
BUT:
"...Michael wished to divorce his wife, Julia, in order to
marry his young mistress, Katarina Konstantinović, the daughter of his first cousin, Princess Anka Obrenović. Both resided at the royal court at his invitation. His plans for a divorce and subsequent remarriage to Katarina met with much protest from politicians, clergy and the general public. His astute and gifted Prime Minister Ilija Garašanin was dismissed from his post in 1867 for daring to voice his opposition to the divorce. However, his divorce never took plac..."

"...On June 10, 1868, Michael was travelling with Katarina and Princess Anka in a carriage through the park of Košutnjak near his country residence on the outskirts of Belgrade.[18] In the park appeared Pavle and Kosta Radovanović in formal black suits, and ponting a loaded gun at the Prince, Kosta approached the carriage. Prince Michael Obrenović recognized him, because of a dispute over his brother Ljubomir. The last words of the Prince, which Kosta himself admitted when on trial were: "Well, it's true." Michael and Anka were shot dead, and Katarina wounded.[19] Further details of the plot behind the assassination has never been clarified; the sympathizers and cousins[20] of the Karađorđević dynasty were suspected of being behind the crime, but this has not been proven..."
"...Anka's granddaughter Natalija Konstantinović was married in 1902 to the Montenegrin Prince Mirko Petrović-Njegoš (1879–1918), whose sister Zorka had married King Petar Karađorđević I in 1883..."