The Relief of Qasr al-Bahili was the successful relief of the small fortress of Qasr al-Bahili and its Arab garrison from the siege by the Turkic Turgesh Khaganate. Sent by the Umayyad governor of Khurasan, an Arab relief force under al-Musayyab ibn Bishr al-Riyahi managed to break the siege and escort the garrison to safety in Samarkand. Although celebrated in the Arabic sources, this exploit also marked the beginning of the Turgesh invasion of Transoxiana, which the Arabs had only recently subdued, and which became a battleground between the two empires until 737.