As a young man, he fought in the Levant under his uncle Ibrahim Pasha. The death of Ibrahim in November 1848 made Abbas regent of Egypt and Sudan. The following August 1849, on the death of his grandfather Muhammad Ali (who had been removed in July 1848 on account of mental weakness), Abbas succeeded him as wāli.
He has been often described as a mere voluptuary, but Nubar Pasha spoke of him as a true gentleman of the "old school". He was seen as a reactionary, morose and taciturn, and spent nearly all his time in his palace. He undid, as far as lay in his power, the works of his grandfather, both good and bad. Among other things he abolished trade monopolies, closed factories and schools, and reduced the strength of the region's army to 9,000 men.