Probably wrote in early 70. Various ancient sources place him as the first, second, or third successor of St. Peter. (Most commonly, he is held to be the third, after Linus and Cletus.) He was the author of a single surviving Letter to the Corinthians, which is often dated around 95, but this is too late a date.
William Jurgens points to internal evidence that places it no later than 80 or so (the date he favors) and possibly up to ten years earlier. John A. T. Robinson shows internal evidence that places it in the first part of the year 70. Specifically, Clement refers to sacrifices still being offered at the temple in Jerusalem, which was destroyed in July of 70. Clement also refers to the repeated crises that have prevented him from writing to the Corinthians until now, which is a likely reference to the violent “year of four emperors” in 69, a time of civil war that followed the forced suicide of Nero in 68. In it Galba, Otho, and Vitellius were successively acclaimed emperor and then killed or forced to commit suicide before Vespasian finally took office.
The epistle may or may not have been written before Clement was pope. He was, in any event, a major figure of the period, as demonstrated by the fact that a number of later works were attributed to him or written about him. Also referred to as “Clement of Rome.”