In 241 AD her father was appointed the head of the Praetorian Guard by the Roman Emperor Gordian III. Timesitheus was known to have great influence over the emperor, who was only 16 years old in 241 AD, having become emperor at age 13 in 238 AD, sponsored in this position by the power of the Praetorian Guard.[4][5] After becoming the head of the Praetorian Guard, Timesitheus "effectively governed the Empire for Gordian".[5] In May of 241 AD, Tranquillina was married to Gordian. She became a Roman Empress and received the honorific title of Augusta.
When Gordian III and Timesitheus went on a campaign against Shapur I of Persia, Tranquillina went with them.[2] Her father died in 243 AD, of unknown but potentially suspicious causes. To replace him, Philip (Marcus Julius Philippus) became head of the Praetorian Guard, and quickly set to plotting to overthrow the young Gordian III.[5] Tranquillina's husband, Gordian III, died in 244 AD under unclear, unknown circumstances, aged only 19.[5] Tranquillina is believed to have outlived both her father and husband, however it is unclear what happened to her afterwards.[2]
^The epitomator of Cassius Dio (72.22) gives the story that Faustina the Elder promised to marry Avidius Cassius. This is also echoed in HA"Marcus Aurelius" 24.
Giacosa, Giorgio (1977). Women of the Caesars: Their Lives and Portraits on Coins. Translated by R. Ross Holloway. Milan: Edizioni Arte e Moneta. ISBN0-8390-0193-2.
Lambert, Royston (1984). Beloved and God: The Story of Hadrian and Antinous. New York: Viking. ISBN0-670-15708-2.
Italics indicates a consort to a junior co-emperor, underlining indicates a consort to an emperor variously regarded as either legitimate or a usurper, and bold incidates an empress regnant.