Hadžić was born on 19 February 1868 in Belgrade,[1] to father Svetozar, a Serbian Army infantry colonel (in the Serbian-Turkish Wars he was the commander of the Čačak and parish brigade), and mother Mileva née Gherman.

[2] He was married in 1901 to Yelisavet-Eola (1879–1966), daughter of Colonel Alexander Simonović and Milica born Spasić, a later court lady of Queen Mary.

In the Great War, he first led the Šumadia Division in combat in Mačva, and in August 1914 he was appointed Chief of Staff of the First Army.

In order to prevent the penetration of Bulgarian-German Turkish forces in Dobruja, the Russian supreme command decided to deploy troops to that part of the front as reinforcement.

The unit arrived from Odessa to the villages of Koru Nasradina and Kara Sinan on 5 September and entered the battle of Dobrich two days later.

[citation needed] Hadžić never forgot the days spent studying, serving and fighting in Imperial Russia.

His appreciation and love for Russia became pronounced after the outbreak of the October Revolution and the Civil War, which led to a large influx of Russian emigrées into Serbia.