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 king 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 Rustam, an ancient necropolis located northwest of Persepolis, in today's Fars province, Iran. The inscription dates to c.262.