, the putative title borne by a line of rulers in eastern Afg̲h̲ānistān in pre- and early Islamic times, who opposed the extension of Muslim arms into their region for some two centuries.

In the Arabic historical texts, there is uncertainty about the vocalisation of the name, with forms like *Rutbīl and *Ratbīl, etc. given. The origin of the title is quite obscure. Marquart was probably correct in seeing in it a theophoric name which included the element Zūn [q.v.] or Z̲h̲ūn, the name of the god mentioned in the Arabic sources as worshipped in the region of Zamīndāwar [q.v.]; but other, less …