This article examines the descriptions of Basīlā in the Kūshnāma (ھمان شوك) and determines the credibility of those descriptions as historical evidence. Kūshnāma is a Persian epic and part of a mythical history of Iran written by Hakim Irānshān b. Abī al-Khayr between 1108 and 1111 CE. Many scholars argue that Basīlā in Kūshnāma can be identified with the Silla Kingdom (57 BCE–935 CE) of ancient Korea for many reasons. First, the descriptions of Basīlā in Kūshnāma largely correspond to those of Sīlā/al-Sīlā in contemporary Islamic texts. Second, in some Muslim historical and geographical works such as Masālek wa Mamālek by Sāed bin Ali Jorjāni (1476 CE), and Ājāyib al-Makhlughāt by Muhammad bin Ahmad Tusi (1161–1178 CE), we find that Basīlā is used, together with Sīlā/al-Sīlā, to describe the same area of the Korean peninsula. With the advent of Islam, references to Korea found in twenty-three Islamic sources written between the ninth and sixteenth centuries by eighteen Muslim scholars, including Ibn Khurdādbih (d. 886 CE), Sulaiman al-Tajir (written around 850 CE), and al-Mas'udi (d. 957 CE), suggest that Muslims' influence had already reached the Korean peninsula by that time.2 Before the discovery of Kūshnāma, however, no documents or epics had been found that describe ancient relations between Iran and Silla in such a detailed manner. In this sense, an in-depth study of Kūshnāma focusing on its descriptions of "Basīlā" will contribute to expanding our understanding of pre-modern relations between the Middle East and Korea. Because both historical events and mythological beliefs of ancient Persia are incorporated in Kūshnāma, this article will consider to what extent we can accept descriptions within Kūshnāma to be reliable historical evidence.