He died on 29th June 1371 during the battle against the Ottomans at Černomen/Marica. The Serbian Emperor Stefan Uroš V bestowed on 9th August 1365 the title of Despot upon him. Ioannes Unklesis enlarged the Simonos Petra-Monydrion and made from it the Simonos Petra-Monastery on the Mount Athos out of gratitude for being awarded with the title. He endowed it with many lands. Ioannes Unklesis issued between 9th August 1365 and October 1368 a chrysobull charter regarding his ktitorial activity in the Simonos Petra-Monastery on Mount Athos, which has been preserved only in the transcription of Kyrillos Lukaris, the Patriarch of Constantinople, from 1622/1623. He designates himself as δεσπότης καὶ αὐτοκράτωρ πάσης Σερβίας καὶ Ῥωμανίας in this charter. He signed the charter in favour of the Zographu-Monastery on the Mount Athos in February 1369 as Ἰωάννης ἐν Χριστῶ τῷ Θεῷ πιστὸς δεσπότης καὶ αὐτοκράτωρ, ὁ Οὔγκλεσης. He designated his reign since March 1368 as βασιλεία. He retained this self-designation till 1371. This self-designation appears in the Slavic documents in the form „carstvo“. He was the groom (ἱπποκόμος) of the Serbian King Stefan Uroš IV Dušan. Ioannes Unklesis, who held the position of grand duke, 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). He signed the document as velik vōevoda. His father was Margnaua (Orbini)/ Margna (Luccari), who was a poor nobleman from Livno in Hum. Ioannes Unklesis was the cousin (ἀνεψιός) of Helene, the Serbian Empress. His brother was Demetrios Blukasinos and his sister was Helene. The husband of his sister was Nikolaos Radochnas (Νικόλαος ῾Ραδόχνας, Nikola Radonja). He was married to Euphemia. Ioannes Unklesis was the son-in-law of Boichnas (Voihna). He was the father of Uglješa, who died as a child. The Serbian King Stefan Uroš IV Dušan took his father and the whole family to the court. The senate of the Ragusan republic (Consilium rogatorum) granted the payment of 50 ducats to Ioannes Unklesis on 22th July 1346 (In consilio rogatorum, in quo interfuerunt 34 consiliarii, captum fuit per omnes, nemine discortante, quod Ugiesse barono huius contrate noviter misso a domino imperatore, pro confirmanda et captanda benivolentia cum ipso ei ut habeat causam bene vivendi cum terra, de avere comunis detur et donetur eidem usque florenos seu ducatos L, prout videbitur d. comiti et suo minori consilio). Ioannes Unklesis governed independently in the are of Serres, Christupolis (Kavala), Philippoi, Drama and Zichnai. He had a good connection to the monks in Mount Athos and acknowledged Sabas, the Protos at the Mount Athos, in 1369 as his spiritual father. The Batopedi Monastery on the Mount Athos obtained at the beginning of the year 1365 from Ioannes Unklesis the Monastery of Theotokos Spelaiotissa in the vicinity of the town Melnik with vineyards and gardens, the village Tzukarades, land near the gate of the Lower Town of Melnik, twelwe subjects within the fortress of Melnik, the village Katunitza, the monydrion Hagios Georgios Aliseres, the village Hagia Kyriake, the village Dempreane, the village Mpusdobos, four mills within the fortress of Melnik, two mills in Katunitza, and other lands in the vicinity of the town Melnik. The Byzantine Emperor Ioannes V Palaiologos issued in September 1365 a chrysobull charter at the request of the Despot Ioannes Unklesis, in which he donated estates in the vicinity of Serres and Kalamaria to the Hilandar Monastery (Ἐπεὶ ὁ περιπόθητος ἀνεψιὸς τῆς ὑψηλοτάτης δεσποίνης Σερβίας καὶ περιποθήτου ἀδελφῆς τῆς βασιλείας μου, εὐτυχέστατος δεσπότης τῆς Σερβίας κῦρ Ἰωάννης ὁ Οὔγκλεσις, ἐζήτησε καὶ παρεκάλεσε τὴν βασιλείαν μου ἵνα γένηται χρυσόβουλλον τοῖς μοναχοῖς τῆς κατὰ τὸ ἅγιον ὄρος τοῦ Ἄθω διακειμένης σεβασμίας μονῆς, τῆς εἰς ὄνομα τιμωμένης τῆς πανυπεράγνου δεσποίνης καὶ θεομήτορος καὶ ἐπικεκλημένης τοῦ Χελανταρίου, καὶ κατέχωσι καὶ εἰς τοεξῆς τὸ περὶ τὰς Σέρρας χωρίον, τὸ καλούμενον τοῦ Ποθολινοῦ, ἔτι τε τὸ ἐν τῇ Καλαμαρίᾳ ἕτερον χωρίον τὸ καλούμενον Λιγνὸν μετὰ τῆς σκάλλας αὐτοῦ). In January 1366 ugodni vlastelin Novakь Mrasorovikь addressed the request to the Serbian Despot Ioannes Unklesis and also to the Serbian King Demetrios Blukasinos to approve his donation of the village Koprivljane to the Monastery Hagios Panteleemon on the Holy Mount Athos. Both of them confirmed the endowment of Novakь Mrasorovikь to the Monastery Hagios Panteleemon on the Holy Mount Athos in a separate chrysobull charter (Sьdrьžeštu mi sia vsa blagověrьnōmu i Bogomь postavlěnnōmu despotu Iōanu Ugleši despotьstvujuštu; blagōvěrьnyi despotь Iōannь Uglešь). The Despot Ioannes Unklesis sponsored the hospital at the Batopedi Monastery and the Esphigmenu Monastery as well. He erected the monydrion of Saint Nicholas at Karyes. He was the ktitor of the small church of Saint Anargyroi at the Batopedi Monastery, where he is portrayed as a patron. The Serbian Despot Ioannes Unklesis confirmed the donation of Kaisar Boichnas (Voihna) for the monk and spiritual father Daniil. He approved all privileges concerning the Church of the Saint Archangels Michael and Gabriel above Gabrovo for him (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….). Ioannes Unklesis donated in April 1369 the village Neōhorь on the plain of Mavrovo with all boundaries and rights to the Monastery of Kutlumus. The monastery obtained all estates, which were in possession of Theōdorь Ōduevikь. The community of monks on the Mount Athos received also pronoia helders with people, land parcels and fruit trees, which were in some way dependent upon Kalabaris (Kalavar) (selo u poli Mavrovьskom imenem Neōhorь sь vsemi megami i s pravinami sela togai, sь vsemь što e drьžalь Theōdorь Ōduevikь pri carstvě mi, i pri Kalavari proniari što su drьžali ili ljudi ili vokie sь vsem periorom sela). At the instance of the monk Theodosios and his confreres from the Monastery Batopedi Ioannes Unklesis pledged to grant in November 1369 120 hyperpyra per annum, extracted from the revenues of the lake of Porou, to the monastery. The Serbian Despot Ioannes Unklesis gave between 1369 and 1371 the selište located between the village Akroterion (Akrotirion) and the river Plumiska as a tax-free property to the Monastery of Batopedi with all rights. The selište was a possession of Lanzo (probably Lantzaretos), who lived at the time as Kalabaris or was bonded by a certain contract with Kalabaris (i darova crtvo mi ōbitěli prstie Bce Vatopedu selište megju Akrotiro, i megju Plumsko šte e drьžalь Lanzo pri Kalavari sь vsemi megjami i pravinami sela toga). The Protaton on Mount Athos gathered in December 1370 at the behest of the Serbian Despot Ioannes Unklesis ruled the dispute over the village of Mpresnitza in favour of the Hilandar Monastery. He endowed in 1370/1371 the Hilandar Monastery with the village Akroterion (Akrotirion) and the katun of Vlachs Zarvince. He gave also pastures and hunting grounds in the vicinity of the village Akroterion and the katun of Vlachs Zarvince to the monastery (I priložihь na jezěre, u prěděle rědinьskōmь, selo Akrotirь i s pašišti i sь lovišti i sь v’sěmi megjami i pravinami sela toga. I selo katunь vlahь imenemь Zar’vin’ce sь v’sěmi pašišti i megjami i pravinami sela togo). Ioannes Unklesis donated in or before 1371 a vineyard and a farmland in the place called Koremistes to the monastery complex Theotokos Kataphygion near Melnik (ἕτερον ἀμπέλιον καὶ ζευγηλατεῖον, εὑρισκόμενα περὶ τὸν τόπον τῆς Κορεμίστης, ἅπερ ἔδωκεν ὁ εὐτυχέστατος δεσπότης Σερβίας ὁ Οὔγκλεσης). In January 1371 Sabas, the Protos at the Mount Athos, granted the small monastery of Makrou to Ioannes Unklesis. In April 1371 Ioannes Unklesis donated the fishpond of Saint Theodore in the lake of Porou with all its possessions and rights, including the fishing privileges in the lagoon, to the Batopedi Monastery. Ioannes Unklesis established the contact with Constantinople in 1367/1368 in order to reconcile with the Ecumenical Patriarchate of Constantinople and to overcome the schism. He therefore received Theophanes, the Metropolitan of Nikaia and at the same time emissary of the patriarch of Constantiople, at his residence. He send im March 1368 a letter to the Patriarchate of Constantinople, which has been preserved in the Register of the Patriarchate of Constantinople. Ioannes Unklesis proposed in the letter that the metropolises in the territory of his realm, among them the Metropolises of Drama, Christupolis, Serres and Zichna should respect the authority of the Ecumenical Patriarchate. Philotheos Kokkinos, the Patriarch of Constantinople, and the Ecumenil synod issued a charter in May 1371, where they officialy proclaimed the Union with the eparchies under the control of Ioannes Unklesis. Philotheos Kokkinos describes him as ὁ εὐτυχέστατος δεσπότης Σερβίας, κῦρις Ἰωάννης ὁ Οὔγκλεσης, τοῦ πλέον τοῖς ἡμετέροις μέρεσιν ἐγγίζοντος τόπου κύριος καταστὰς, ἄνθρωπος ὑπάρχων φρόνιμος καὶ καλὸς καὶ τρόπου καὶ συνειδήσεως ἀγαθῆς καὶ τὸν τοῦ θεοῦ φόβον κεκτημένος, ἠθέλησεν ἐπανασώσασθαι τὰς ἐκκλησίας ταύτας τῇ ἰδίᾳ μετρὶ καὶ κεφαλῇ τῶν ἐκκλησιῶν. Demetrios Blukasinos and his brother Ioannes Unklesis commanded the Serbian forces, which fought against the Ottoman army commanded by the Beglerbeg Lala Şahin Pasha and Evrenos near the village Černomen on 26th September 1371. His name is attested in the brebion (memorial book), which has been preserved at Protaton in Karyes on Mount Athos (Protaton 340 [113], 1v: Ἔτι δεόμεθα ὑπὲρ μακαρίας μνήμης καὶ ἀφέσεως τῶν ἁμαρτιῶν τῶν ἀειμνήστων δούλων τοῦ Θεοῦ Δημητρίου κράλη καὶ Ἰωάννου δεσπότου καὶ τῶν σὺν αὐτοῖς ἀναιρεθέντων ὀρθοδόξων χριστιανῶν).