| Conflict: | Battle of Mastara |
| Place: | Mastara,Armenia |
| Partof: | Caucasus campaign of WW1 |
| Date: | 24–28 May 1918 |
| Combatant1: | Armenian National Council |
| Combatant2: | Ottoman Empire |
| Strength1: | 3000 |
| Strength2: | 8000 |
| Casualties1: | 500 |
| Casualties2: | 2000 |
| Commander1: | Drastamat Kanayan |
| Commander2: | Wehib Pasha |
| Result: | Armenian victory |
Battle of Mastara[1] was a military battle fought by the Armenian National Council and the Ottoman Empire, it took place between 24 and 28 May 1918, and was one of the battles which resulted to the formation of the First Republic of Armenia.[2]
The battle began on the 24 May 1918, when Ottoman troops approached the Armenian garrison of only 3,000 men commanded by Drastamat Kanayan in Mastara, the Ottoman army had much more weapons and soldiers, however they were not as moralized as the Armenians were.[3]
The Ottomans had begun their assault, and by 25 May heavy fighting was occurring in Mastara, the Ottomans were however unable to properly break the defensive line of the Armenians, whom used the Church of Saint John to command the defensive line. After two failed Ottoman attacks from May 24–25, they decided to assault the Church of Saint John directly, due to its importance for the Armenian troops both culturally and for the sake of the battle's command, the Ottoman attack began on the night of May 26, with Ottoman troops seeing initial successes, breaking through the Armenian defensive line for the first time and rapidly advancing towards the church. The Armenians however did not easily give up on, as they fought bravely, using grenades and hit and run tactics against the Ottomans in the fairly fortified city, suffering hundreds of casualties in the process but being successful in the defense, as Ottoman troops were forced to retreat outside of the city, back to their original positions. Following this failed attack by the Ottomans, their morale continued to deplete, with Ottoman troops regularly deserting during the battle which forced the Ottomans to retreat after more breakthrough attempts between 27 and 28 May had horribly failed.