It it doubtful, that he is the same person as „lo jupan Voichna“, who appears in the charter of Vladislav, the son of the former Serbian King Dragutin, adressed to Ragusan authorities from the 25th October 1323. The confirmed terminus ante quem of his decease is September 1370/August 1371 (Prišьdšu že mi vь hramě prěsvetije Bogorodice Hilan’darě, i viděvь grobь gospodina mi i roditelja svetopočiv’šega kesara). It is possible that he was already death in 1369, because the Serbian Despot Ioannes Unklesis (Jovan Unglješa) approved in this year the donation of the Church of the Saint Archangels Michael and Gabriel above Gabrovo granted by Kaisar Boichnas (Voihna) for the monk and spiritual father Daniil (Kako pride kь carьstvu mi čьstni starьcь duhovьnikь kyrь Daniil…Mihaila i Gabrila više Gabrova, i prinese mi zapisanie gospodina….roditelě mi kesara, i viděhь pročtohь čto jestь zapisalь i….kesarь Voihna, i ini hristoljubivi crьkvi onoizi ljud…..zemle: bystь hotěnije carьstvu mi kudě godě mu se što nahodi……hru….ljud…..vinogradь, perivolja, ili i mlinь, ima hotěnije carьstvo mi kako da je……vь věkomь, i da jestь pace svobodna, nikiimь nepotьknovlenno….). He appears as vlastelinь, surodnikь carьstva mi bratučedь Voih’na in the charter of the Serbian King Stefan Uroš IV Dušan for the Hilandar Monastery from 1348. He is mentioned as kaisar/kesar in 1351 (Voicha chiessar) and 1355 (Voichna chiesar) in two forged documents of the Serbian Emperors for the town Kotor translated into old Italian. Attested as kaisar and kesarь from 1357 to 1371 (Βοΐχνας ὁ Καῖσαρ). He was the governor of the town Drama in 1357 according to the Byzantine historian Ioannes Kantakuzenos (ὁ δὲ τῆς πόλεως, ἧς ἦρχεν, ἀποδημῶν, Δράμα δὲ ἦν). Sima Ćirković suggests that he held unter his control a much bigger region corresponding with the ruling area of his son-in-law, the Serbian Despot Ioannes Unklesis (Jovan Unglješa). In a later charter of Iakobos Kutaches Philanthropenos Tarchaneiotes from 1405 he is erroneously described as κράλης. His daughter was Euphemia (Jefimija/Elena). He was the father-in-law of the Serbian Despot Ioannes Unklesis (Jovan Unglješa). The Serbian King Stefan Uroš IV Dušan confirmed in 1348 at the intervention of his nobleman and most probably also relative Voih’na the previous donation of the village Potolino in the valley of the river Struma to the Hilandar Monastery (I tu vьspomenu carstvu mi vlastelinь, surodnikь carьstva mi bratučedь Voih’na, ō izvěstneišemь po utvrьždeni sela Potolina, iže bě priložilo i po prěžde carьstvō mi Hilan’daru...I po blagosrьdnomu moljeniju i blagoutrobiju kь v’semь svetimь i božьstvnimь crьkvamь bratučeda mi Voih’ne, darova carьtvō mi vь postrum’skomь prědělě: Seloō Potolinovo sь zasel’ci i periōromь, s megjami i sь dohoci sь v’semi pravinami sela togoō). After the death of the Serbian Emperor Stefan Uroš IV Dušan he was a prominent figure in the circle of the Dušan’s widow Jelena (Helene). He encouraged Mathaios Kantakuzenos at first to invade the territory of Eastern Macedonia. He then betrayted him and joined the army of Serbian Emperor Stefan Uroš V. He defeated Mathaios Kantakuzenos at Philippoi in Macedonia in 1357. Mathaios Kantakuzenos was imprisoned by him. He handed over Mathaios Kantakuzenos in summer 1357 to the Byzantine Emperor Ioannes V Palaiologos for a ransom. The Serbian Despot Ioannes Unklesis (Jovan Unglješa) confirmed in 1358 an endowment of his mother-in-law, the wife of Boichnas, for the Kutlumus Monastery (ὅπερ ἐπροσίλοσεν ἡ ἁγία μου κυρία ἡ Κεσάρισα πρὸς αὐτὴν τὴν μονὴν ἐν τι τοποθεσία τὴ ἐπικεκλημένι ἡ Προυνέα χάριν ψυχηκὴς δωρεὰς αὐτῆς ζευγαρίων τεσσάρον... ἐγὼ Οὔγλεσις μέγας βοεβόδας ἀπὸ τὴς αὐτοῦ ἐλεημοσίνης τοὺ αὐθέντου ἡμῶν τοὺ πανευτυχεστάτου δεσπότου καὶ τοὺ ἀδελφοὺ αὐτοὺ τοὺ [...τ...]ου μου στέργο καὶ βεβεῶ τὰ τιαύτα χωράφια εἰς τὴν Προυνέαν γὴν ζευγαρίων τεσάρον ὅπος νέμωσην οἱ τιαύτοι μοναχοὶ τὴς θείας βασιλεικῆς μονῆς τοὺ Κουτλουμούσι ἀκολείτος). The Metropolitan of Drama in 1359 gave his consent to return the metochia of Theotokos Koriliotissa and Hagioi Anargyroi to the Batopedi Monastery after the involvment of Boichnas and his wife. Boichnas and his wife endowed the Batopedi Monastery with the church of Saint Photeine. Boichnas was buried in the Hilandar Monastery at Mount Athos.