Ways in which the name of khan Omortag has been written in the historical sources: Moragvn, Omortag, Муртагонъ
Omortag takes over after the death of his father – khan Krum. In 816, he signs a 30-year peace treaty with The Byzantine Empire, which he observes till the end of his life. During the agreement of the treaty, the emperor takes an oath in the Bulgarian custom, and the khan – in Byzantine one.
In 823 khan Omortag helps the Byzantine emperor Michail II in his fight with the usurper Toma, called the Slav. A year later, he is compelled to send his armies on the northeast, at the boundary with the khazars. The sources about that war, however, are extremely vague.
In the period 824-829 khan Omortag leads sustained negotiations with the Emperor of the Franks Ludovik /Loui/ Pious for settling the argument on the northwestern border: the tribes of abodits and timochans decide to separate from the Bulgarian power depending on the centralistic policy of the khans. The delay on behalf of the Franks forces the Bulgarian ruler to settle the argument by means of “sword and fire”. Thus, the lands of the Middle Danube remain under Bulgarian power until the end of the First Bulgarian Kingdom /1018/.
Khan Omortag undertakes construction works of a large-scale: he rebuilds the capital Pliska, which has been burnt at the invasion of the emperor Nikifor I Genik /811/, out of stone; he erects new palaces /ceremonial halls/. The massive buildings have been commemorated by stone inscriptions, emphasizing the ruler’s self-esteem and as well as the fact that the Bulgarian master has been chosen by God. In succession of his ancestors’ policy, Omortag favours the atmosphere of religious tolerance in the khandom. He shows no mercy only to the captives, who are willing to organize conspiracies against his power.
Khan Omortag goes even further regarding the process of centralization of his country, as he initiates a new territorial separation. On the head of the administrative areas, called comitats, he places bouils, faithful to the ruler, called comitas. The comitas probably had the privilege to share the table with the khan.
The circumstances in which Omortag dies are not clear. He has three sons – Enravota /Voin/, Zvintsa /Svintsa/ and Malamir. For unknown reasons, his youngest son – Malamir – succeeds him. Khan Malamir issues an order that his eldest brother should be beheaded, because of Enravota’s devotion to Christianity.