The Rev. John W. O’Malley, a Jesuit scholar whose depth of learning, clarity of prose and analytic prowess regarding topics as divergent as late-medieval rhetoric and the lasting impact of the Second Vatican Council earned him a reputation as the dean of Catholic historians, died on Sept. 11 in Baltimore.

Father O’Malley joined the Jesuits at 18 and later earned a doctorate in history from Harvard, and throughout his 55-year academic career he commanded respect among both the faithful and the secular. Church leaders considered him a go-to authority, as did the Renaissance Society of America, an academic association that elected him president in 1998.