He came into conflict with the Souliotes (1789, 1792-3), but was defeated at all fronts. In 1796, he annexed the region of Arta. In 1798, he conquered the areas of Chimarra, Vouthroto, Preveza and Vonitsa. In 1800, he fought again against the Souliotes. After an extremely difficult campaign, he managed to expel them from Souli. In 1809-12, he completely subjugated Northern Epirus and Southern Albania. His realm extended to Peloponnese. In 1819 he conquered Parga.
His government was tyrannical. His personal abilities were remarkable (quick thinking, sharpness, determination). He transported and applied many of the technical evolutions of the developed countries to his realm, whilst he was free from religious prejudices. The frequent visits by European travellers who wanted to meet him in person and the books referring to his life and acts by European writers and men of letters, speak for the glory of Ioannina during his period. Four consulates of the Great Powers (France, England, Russia and Austria) existed in Ioannina. At the beginning of the second decade of the 19th century, at the height of his power, he ruled Epirus, Aetoloakarnania and half of the modern Albania, i.e., an area with a population of about 1,500,000 people.
The ambitious plans of Ali Pasha to become independent became known to the Sublime Port, and Sultan Mahmoud II declared Ali guilty of betrayal. He assigned the leadership of his troops to Ismael Pasobey, an implacable enemy of Ali, who arrived to Ioannina and proceeded with the siege of the castle (autumn 1820). The successor of Ismael, Hoursit Pasha, tricked Ali and persuaded him to capitulate and retreat to the Island of Ioannina (January 1822), where he was killed during a fight with representatives of the Sultan.