It existed between March 4 and April 15, 1918 and was formed to protect the Republic from the German-Austrian Army, which entered the territory of Ukraine at the invitation of the leadership of the Ukrainian People's Republic.
Soon, the volunteer Donetsk miners and workers were joined by soldiers from the former Russian 8th Army of the Romanian front and Anatoliy Gekker became the commander of the Donetsk Red Army.
On March 16, 1918, the Council of People's Commissars issued a "Decree of hostilities", where it announced "the entry of the Republic into the South Russian military alliance in order to jointly fight against the German occupation".
Initially, the Donetsk Army defended the north-Donetsk railway, and from the middle of April it defended the line between the village of Borova, the river Oskol, the river Donets and Yaremche.
By the end of the month, it fought in skirmishes against German troops in the region of Lugansk-Rodakovo, together with the 5th Army of the Ukrainian People's Republic under the command of Kliment Voroshilov.