For the reigns of the Nicene emperors, more especially of John Vataces and his son, their minister, George Acropolita, is the only genuine contemporary; but George Pachymer returned to Constantinople with the Greeks at the age of nineteen (Hanckius de Script. Byzant. c. 33, 34, p. 564-578. Fabric. Bibliot. Graec. tom. vi. p. 448 - 460). Yet the history of Nicephorus Gregoras, though of the 14th century, is a valuable narrative from the taking of Constantinople by the Latins.