The Battle of Karakilisa (Armenian: Ղարաքիլիսայի ճակատամարտGharakilisahi chakatamart, Turkish: Karakilise Muharebesi or Karakilise Muharebeleri) was a battle of Caucasus Campaign of World War I that took place in the vicinity of Karakilisa (now Vanadzor), on May 25-28, 1918.
The outnumbered Armenian defenders managed to turn back the invading Ottoman forces, which broke the armistice, signed on December 1917, with Transcaucasian commissariat entering Western Armenia, conquering Erznka, Erzerum, Sarighamish, Kars and Alexandropol and reaching Karakilisa. The victory here as well as at Sardarabad and Abaran were instrumental in allowing the Democratic Republic of Armenia to come into existence.
In several months, the cities of Erznka, Erzerum, Sarıkamış, Kars and Alexandropol were conquered. On May 20, they conquered the Akhbulag, Djrajur and Kaltakhchi villages. On May 21, they conquered Vorontsovka. Pressed by the Turkish regular army, Armenian forces were retreating. Part of Osman-Turkish forces moved to Yerevan, another one to Karakilisa. The latter forces included about 10 thousand soldiers, 70 pieces of artillery and 40 machine-guns. The Armenian population was leaving their homes moving to the south to Yerevan and Syunik. Garegin Nzhdeh (with his troops) reached Karakilisa and managed to unite the population for the fight. The Armenian forces reached the number of 6 thousand, with 70 pieces of artillery and 20 machine-guns. After a violent battle of 4 days, on May 25-28, both sides had serious losses. Although the Ottoman army managed to invade Karakilisa and massacre all its population of 4,000 souls, it had no more forces to intrude farther into Armenian territories. 
We do not have the strength to defeat the Armenians. The three day battle in Karakilise shows that as long as their existence is in danger they will prefer to die fighting. We must not bring on a battle with the force that 1,200,000 Armenians can raise. If the Georgians join in the hostilities, it will be impossible to advance... In short, we must come to terms with the Armenians and Georgians.