Jiǎ Dān 賈耽 (730–805), courtesy name Dūnshī 敦詩, was a Tang statesman and geographer from Nánpí 南皮 (Cāngzhōu). He rose through provincial governorships (Liángzhōu, Shānnán, Yìchéng) and entered the central chancellery in 793, serving as 左僕射 / 同中書門下平章事 from 793 until his death in 805 under emperors Dézōng 德宗 and Shùnzōng 順宗. He is best known to historians of cartography and geography for his Hǎinèi Huáyí tú 海內華夷圖 (801), a large grid-based world map continuing the tradition of Péi Xiù 裴秀, and for the Guǎngzhōu tōnghǎi yídào 廣州通海夷道, the earliest surviving description of the maritime route from Guangzhou via the Strait of Malacca to the Persian Gulf, preserved in Xīn Tángshū 43. His official biographies are at Jiù Tángshū 138 and Xīn Tángshū 166. In Buddhist apocryphal literature his name was used as an authorizing imperial voice in late-Tang Dunhuang “warning sūtras” (e.g. KR6u0052 Quànshàn jīng 勸善經 and KR6u0053 Xīn púsà jīng 新菩薩經), where his title 左丞相 frames the prophecy as a chancellor’s edict urging copying of the text to ward off epidemic disease.