Shapur I's inscription at the Ka'ba-ye Zartosht

Shapur I's Ka'ba-ye Zartosht inscription (shortened as Shapur-KZ, ŠKZ, SKZ), also referred to as The Great Inscription of Shapur I, and Res Gestae Divi Saporis (RGDS), is a trilingual inscription made during the reign of the Sasanian Shah Shapur I (r.240–270) after his victories over the Romans. The inscription is carved on the Ka'ba-ye Zartosht, a stone quadrangular and stepped structure located in Naqsh-e Rostam, an ancient necropolis located northwest of Persepolis, in today's Fars province, Iran. The inscription dates to c. 262. It is the first lengthy inscription by any Sasanian ruler and provides information on Shapur's religious beliefs, lineage, the territories which he ruled and his defeat of the Romans.