Timesitheus, having started his career under the Severan dynasty emperor Elagabalus, has held a number of important provincial postings.

Adept at finances, he had served in Spain as a Promagistrate.

Between 218-222, the emperor had promoted him and appointed him as Procurator of Arabia and from 220 he became a Prefect of the Cohorts and had held procuratorships in Syria, Palestine, Bithynia, Pontus, Paphlagonia, Asia, Germania Inferior, Gallia Belgica, Gallia Aquitania and Gallia Lugdunensis, proving to be an able and efficient official.

In 241, Gordian III, seeking a responsible person to serve as Praetorian Prefect and head of the Praetorian Guard, picks Timesitheus and appoints him to the position.

Timesitheus is to be an important, responsible and prominent figure in the emperor’s reign and through his years of political experience is able to assist Gordian and Gordian’s mother Antonia Gordiana in administering the Roman Empire.

An example of Timesitheus’ suitability in his position is that in May 241, Timesitheus had arranged with Gordian to marry his daughter Tranquillina.

The wife of Timesitheus is unknown.

His daughter becomes a Roman Empress and her marriage to the young Gordian will prove to be a very happy (albeit short-lived) union.

Timesitheus, proving to be a figure that will work with the emperor, not against him, orders the improvements of the empire’s borders in Africa.

The Prefect begins to organize war on Persia, whose King Shapur I had recently invaded Roman Mesopotamia and captured Nisibis and Carrhae.