Edwin G. Pulleyblank
Although Richard N. Frye reports that the word "was probably foreign to Sogdian", Gerhard Doerfer points out that even in Turkic languages, its plural is not Turkic (sing. "tarxan" --&gt; plur. "tarxat"), suggesting a non-Turkic origin. L. Ligeti comes to the same conclusion, saying that "tarxan and tegin [prince] form the wholly un-Turkish plurals tarxat and tegit" and that the word was unknown to medieval western Turkic languages, such as Bulgar. Taking this into consideration, the word may be derived from medieval Mongolian "darqat" (plural suffix "-at"), itself perhaps derived from the earlier Sogdian word "*tarxa"n"t" ("free of taxes"). A. Alemany gives the additional elaboration that the related East Iranian Scythian (and Alanic) word "*tarxan" still survives in Ossetic "tærxon" ("argument, trial") and "tærxon kænyn" ("to judge"). Harold Walter Bailey also proposes an Iranian (Khotanese Saka) root for the word, L. Rogers and Edwin G. Pulleyblank argue that the word may have originated among the Xiongnu, as a pronunciation of the word recorded in Old Chinese as chanyu, which Pulleyblank argues may have originally represented a Chinese approximation of "dān-ĥwāĥ" for "*darxan".