The detailed History of George Akropolites covers events from 1203 to 1261, and is an indispensable source for the history of the empire of Nicaea. The main narrative opens with a discussion of the Fourth Crusade and the sack of Constantinople. It then follows the reigns of the Byzantine emperors in Nicaea: Theodore I Laskaris, John III Vatatzes, Theodore II Laskaris, and Michael VIII Palaiologos. The history ends with events following Michael VIII's conquest of Constantinople in 1261.

The text focuses on the lives of the emperors and diplomatic and military history, dwelling particularly on the attempt to reconquer lost territory. It provides an extensive account of the trial of the future emperor Michael VIII for treason. Akropolites presents autobiographical details frequently throughout the text. He was an eyewitness to many of the events he describes. Aside from his own personal experience, he appears to have drawn on official documents and may have relied on other historical accounts, but he never names these explicitly. Akropolites's writing style has been described as concise and unadorned, as well as carefully organized along chronological and geographic lines. Although Akropolites claims to provide an objective account, Macrides has argued that he used the History to dissociate himself from the Laskarid dynasty, whose members he sharply critiques, and to present Michael VIII as the empire's legitimate ruler. He did so, Macrides believes, in order to retain the latter's favor at court.

The History as we have it seems incomplete. It ends in mid- sentence while covering the events of 1261, and in other ways seems unrevised. It is possible that Akropolites intended to write more. Alternatively, part of the text may have been destroyed by Akropolites’ anti- unionist detractors.

Knowledge of George Akropolites's biography mostly derives from his History, in which he frequently incorporates his own life's story into the narrative. He was born in Constantinople in 1217 to a relatively wello off family with a tradition of working in the civil service, although his father's precise occupation is not known. Akropolites began his schooling in Constantinople. At the age of sixteen, his father sent him to Nicaea.