ALEXANDER SEVERUS, emperor of Rome, succeeded Heligobalus about A. D. 222, when but 16 years of age. His mother's name was Mammæa, and by her advice he in a great measure regulated his conduct. He applied himself to the reformation of abuses, the state having been greatly disordered by the vicious conduct of his predecessor. He was a most strict lover of justice, an encourager of learning and learned men, and favourable to the Christians. He made a successful expedition against the Persians; but endeavouring to reform his troops, who had grown very licentious under the late bad government, they murdered him at the instigation of Maximinus, in the 29th year of his age, together with his mother, A. D. 235.