English: Tadmur (Arabic: تدمر‎; ancient Palmyra, Homs Governorate). Map of the territorial changes during the first 7 days of the Tadmur offensive. Since Syrian rebels and al-Nusra Front were gaining ground in the Idlib Governorate, the Syrian Government redeployed forces from the Homs Governorate to the the Idlib Governorate; however, ISIL took advantage of the troop movement to launch an offensive in the Tadmur region. On the day the offensive began, on May 13, ISIL captured 30% of the Homs Governorate's Tadmur District, advancing around 100 miles in some areas. On May 14, ISIL entered the northern part of Palmyra city, and clashes erupted until the Syrian Army expelled ISIL from the city on May 16. From May 16-18, ISIL captured the T3 Pumping Station, and captured some towns to the west of Palmyra, while putting other neighboring towns to the north-northwest of Palmyra under siege. However, on May 20, ISIL captured Tadmur, the ruins of Palmyra, the town of Ameriya, and the surrounding towns to the north and the east. During the next 6 days, ISIL advanced even further westward, solidifying their control of the region around Palmyra, and capturing a stretch of land to the south of Qaryatayn. On May 20, ISIL broke through Syrian Army lines and attacked the Tiyas T4 Airbase, until Syrian Army forces repelled the attack 4 days later. ISIL also managed to advance southward from their territory to the east of Homs, capturing the city of Furqlus on May 22. On May 26, the Syrian Army sent reinforcements to the region, stemming the ISIL advance, and pushing towards the frontline to the north and the south of Palmyra.

The red dashed lines outline the original frontline boundary prior to the Tadmur offensive. The arrows indicate the troop movements carried out by both sides. The red arrows symbolize the Syrian Armed Forces troop movement, while the black arrows symbolize ISIL troop movement. The size of the arrows indicate the size of the moving forces proportionally. The red arrows show the initial Syrian Army redeployment to Idlib, and the Syrian Army retreats and reinforcements, while the black arrows indicate the directions of the offensive launched by ISIL.