Toudounos 1 is not a proper name but a title, "tudun"; see Dunlop, Jewish Khazars, p. 174 with n. 16 ("The "tudun" appears to have been a governor appointed by the Khazar central authority, distinct from the "elteber", or semi-independent hereditary prince, as among the Bulgars"); see also Mango and Scott, Theophanes, p. 530 n. 5.

Governor of Cherson and representative of the khagan of the Khazars (Τουδοῦνον δέ, τὸν ἄρχοντα Χερσῶνος ὡς ἐκ προσώπου τοῦ Χαγάνου ὄντα: Theoph. AM 6203; Τουδοῦνον δὲ τὸν Χερσῶνος ἄρχοντα: Nic. Brev. de Boor 45, Mango 45:16-17); in 710 he was sent to the emperor Justinian II (Ioustinianos 1) by Stephanos 5 for punishment together with Zoilos 1 and other leading citizens of Cherson with their families: Nic. Brev. de Boor 45, Mango 45:16-17, Theoph. AM 6203. When subsequently in 711 the new authorities in Cherson revolted against Justinian II (Ioustinianos 1) and sought Khazar aid, the emperor sent an expedition to restore Toudounos 1 and Zoilos 1 to their offices (ταῖς οἰκείαις ἀρχαῖς: Nic. Brev. de Boor 45-46, Mango 45:42) (cf. Georgios 3 and Ioannes 8); they were captured by the people of Cherson and sent to the Khazars, though Toudounos 1 died on the journey: Nic. Brev. de Boor 45-46, Mango 45, Theoph. AM 6203. On these events, cf. Dunlop, op. cit., pp. 173ff.

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