[2] With the death of his father in 1884 Prince Alexis became head of the senior branch of the House of Karageorgevitch and a claimant to the Serbian throne.

A couple of years later his brother Prince Bojidar made a secret visit to Serbia to gather support for the House of Karageorgevitch.

[5] One of the reasons speculated on was that her family were concerned that their daughter would merely be a morganatic wife in the event Prince Alexis ascended the Serbian throne.

As a result, Prince Alexis announced in an interview that he had abandoned his claim to the throne and by that betraying the wishes of his ambitious mother.

Determined to serve he received King Peter's permission and trimming his moustache to disguise his features enlisted into the Serbian Army as a private soldier.

[13] As a result, Princess Sara, his mother, who thought the marriage was a mésalliance and was against it from the start, broke all communication with her eldest son.

[15] After the fall of the wartime capital Niš to the Central Powers Prince Alexis and his wife had to take part in the mass retreat from Serbia through the treacherous mountains of Montenegro and Albania in the winter of 1915–1916.

[citation needed] With the death of Prince Alexis in 1920 during the final year of the worldwide Spanish flu pandemic, the male line of the senior branch of the Karageorgevitch dynasty became extinct.