Maximinus Thrax (Gaius Julius Verus Maximinus  c. 173 – 238) was a Roman emperor from 235 to 238. Born of Thracian origin – giving the nickname "Thrax" ("the Thracian") young Maximinus entered the Roman military in 190 CE, and due to his enormous size and great strength, he quickly rose through the ranks.

While it’s not clear precisely how large Maximinus was (some historic sources claim a likely well exaggerated equivalent of eight and a half feet tall), Maximinus was widely reported as towering over his contemporaries both in height and muscular girth. Often depicted with an extraordinary large brow, nose and jaw, and with most reports agreeing that he was “of… frightening appearance and colossal size,” many theorize he may have suffered from acromegaly or gigantism.

Ultimately Maximus held high command in the army of the Rhine under Emperor Severus Alexander. After Severus was murdered in 235, he was proclaimed emperor by the army, beginning the Crisis of the Third Century.

His father was an accountant in the governor's office and sprang from ancestors who were Carpi (a Dacian tribe), a people whom Diocletian would eventually drive from their ancient abode (in Dacia) and transfer to Pannonia.  Maximinus was the commander of the Legio IV Italica when Severus Alexander was assassinated by his own troops in 235. The Pannonian army then elected Maximinus emperor.

Maximinus' ancestry remains an open question. His background was that of a provincial of low birth, and he was seen by the Senate as a barbarian, not even a true Roman, despite Caracalla’s edict granting citizenship to all freeborn inhabitants of the Empire.  According to the Augustan History, he was a shepherd and bandit leader before joining the Imperial Roman army, causing historian Brent Shaw to comment that a man who would have been "in other circumstances a Godfather, became emperor of Rome."  In many ways, Maximinus was similar to the later Thraco-Roman emperors of the 3rd–5th century (Licinius, Galerius, Aureolus, Leo I, etc.), elevating themselves, via a military career, from the condition of a common soldier in one of the Roman legions to the foremost positions of political power. He joined the army during the reign of Septimius Severus.

Maximinus  was a so-called barracks emperor of the 3rd century; his rule is often considered to mark the beginning of the Crisis of the Third Century. Maximinus was the first emperor who hailed neither from the senatorial class nor from the equestrian class.

Maximinus was in command of Legio IV Italica, composed of recruits from Pannonia, who were angered by Alexander's payments to the Alemanni and his avoidance of war.  The troops, who included the Legio XXII Primigenia, elected Maximinus, killing Severus Alexander and his mother at Moguntiacum (modern Mainz).  The Praetorian Guard acclaimed him emperor, and their choice was grudgingly confirmed by the Senate,  who were displeased to have a peasant as emperor. His son Maximus became caesar.

In 238 (which came to be known as the Year of the Six Emperors), a senatorial revolt broke out, leading to the successive proclamation of Gordian I, Gordian II, Pupienus, Balbinus, and Gordian III as emperors in opposition to Maximinus. Maximinus advanced on Rome to put down the revolt, but was halted at Aquileia, where he was assassinated by disaffected elements of the Legio II Parthica.