Humanities › History & Culture The Theodosian Code A Significant Body of Laws through the Middle Ages Share Flipboard Email Print Clio20/Wikimedia GNU Free Documentation License 1.2 History & Culture Medieval & Renaissance History People & Events Daily Life American History African American History African History Ancient History and Culture Asian History European History Genealogy Inventions Latin American History Military History The 20th Century Women's History View More By Melissa Snell History Expert B.A., History, University of Texas at Austin Melissa Snell is a historical researcher and writer specializing in the Middle Ages and the Renaissance. She authored the forward for "The Complete Idiot's Guide to the Crusades." our editorial process Melissa Snell Updated February 25, 2019 The Theodosian Code (in Latin, Codex Theodosianus) was a compilation of Roman Law authorized by Eastern Roman Emperor Theodosius II in the fifth century. The code was intended to streamline and organize the complicated body of imperial laws promulgated since the reign of Emperor Constantine in 312 C.E., but it included laws from much further back, as well. The code was formally begun on March 26, 429, and it was introduced on February 15, 438. Codex Gregorianus and Codex Hermogenianus In large part, the Theodosian Code was based on two previous compilations: the Codex Gregorianus (the Gregorian Code) and the Codex Hermogenianus (the Hermogenian Code). The Gregorian Code had been compiled by the Roman jurist Gregorius earlier in the fifth century and contained laws from Emperor Hadrian, who reigned from 117 to 138 C.E., down to those of Emperor Constantine. The Hermogenian Code The Hermogenian Code had been written by Hermogenes, another fifth-century jurist, to supplement the Gregorian Code, and it focused primarily on the laws of the emperors Diocletian (284–305) and Maximian (285–305). Future law codes would, in turn, be based on the Theodosian Code, most notably the Corpus Juris Civilis of Justinian. While Justinian's code would be the core of Byzantine law for centuries to come, it wasn't until the 12th century that it began to have an impact on western European law. In the intervening centuries, it was the Theodosian Code that would be the most authoritative form of Roman law in western Europe. The publication of the Theodosian Code and its rapid acceptance and persistence in the west demonstrates the continuity of Roman law from the ancient era into the Middle Ages. The Foundation of Intolerance in Christendom The Theodosian Code is particularly significant in the history of the Christian religion. Not only does the code include among its contents a law that made Christianity the official religion of the Empire, but it also included one that made all other religions illegal. While clearly more than a single law or even a single legal subject, the Theodosian Code is most famous for this aspect of its contents and is frequently pointed to as the foundation of intolerance in Christendom. Also Known As: Codex Theodosianus in LatinCommon Misspellings: Theodosion CodeExamples: A great many earlier laws are contained in the compilation known as the Theodosian Code.