It was signed on 9 December 1917 in Focșani in Romania.Romania had entered World War I in August 1916, invading Austria-Hungary in an attempt to seize Transylvania.

However, the Central Powers launched a successful counteroffensive in September 1916, capturing Bucharest and occupying approximately two thirds of the Romanian territory by December 1916.

The Romanian government was forced to retreat to Iași, in the historical region of Moldavia, but was able to stave off complete collapse thanks to the numerous Russian reinforcements that had been sent to Romania to prevent a Central Power invasion of southern Russia at the beginning of 1917, and later, in spite of the unwillingness of the Russian troops to continue fighting, thanks to the successful repulse of the Central Powers' offensive at Mărășești and Oituz.

[2][3] After the October Revolution of 1917, Russia fell into civil war, and the Russian government began withdrawing its troops from Romania.

[2][4] The resulting truce was signed on 9 December 1917 in Focșani on the Siret River, which was the site of the main Romanian defensive line.