He was a younger son of the shah, Feth Ali, but on account of his mother's royal birth was destined by his father to succeed him. Entrusted with the government of a part of Persia, he sought to rule it in European fashion, and employed officers to reorganize his army. He was soon at war with Russia, and his aid was eagerly solicited by both England and Napoleon, anxious to checkmate one another in the East. Preferring the friendship of France, Abbas continued the war against Russia, but his new ally could give him very little assistance, and in 1814 Persia was compelled to make a disadvantageous peace. He gained some successes during a war between Turkey and Persia which broke out in 1821, but cholera attacked his army, and a treaty was signed in 1823. His second war with Russia, which began in 1825, was attended with the same want of success as the former one, and Persia was forced to cede some territory. When peace was made in 1828 Abbas then sought to restore order in the province of Khorasan, which was nominally under Persian supremacy, and while engaged in the task died at Meshed in 1833. In 1834 his eldest son, Mahommed Mirza, succeeded Feth Ali as shah. Abbas was an intelligent prince, possessed some literary taste, and it noteworthy on account of the comparative simplicity of his life.
From Encyclopedia Britannica (1911)