Short answers, pulled from the story.
Gaius was a Roman jurist who flourished between approximately AD 130 and 180, during the reigns of Hadrian, Antoninus Pius, Marcus Aurelius, and Commodus. Almost nothing is known about his personal life; even his full name is uncertain, as Gaius or Caius is merely a praenomen, a personal first name. After his death, Emperor Theodosius II named him in the Law of Citations as one of five jurists whose opinions judges were required to follow.
Gaius wrote the Institutes, an introductory legal textbook composed around AD 161 and divided into four books covering persons, property and wills, succession and obligations, and legal actions. He also wrote treatises on the Edicts of the Magistrates, the Twelve Tables (Ad Legem XII Tabularum), and the Lex Papia Poppaea. His Institutes served as the standard Roman law textbook for roughly three centuries and was the direct model for the later Institutes of Justinian.
The Institutes of Gaius was rediscovered in 1816 by B. G. Niebuhr in the chapter library of Verona. It was found as a palimpsest, a manuscript in which the text of the Institutes had been scraped away and overwritten with works of St. Jerome. The first printed edition, the editio princeps, was published by I. F. L. Göschen in Berlin in 1820.
The Law of Citations was issued by Emperor Theodosius II and named five jurists, including Gaius, Papinian, Ulpian, Modestinus, and Paulus, whose opinions judicial officers were required to follow when deciding cases. This gave Gaius's writings formal legal authority across the late Roman Empire. His works were also extensively quoted in the Digest compiled by Tribonian under Justinian I, making them a permanent part of the Corpus Juris Civilis.
Gaius generally aligned with the Sabinian school of Roman jurisprudence, which traced its intellectual lineage to Ateius Capito, a figure mentioned in the Annals of Tacitus. The Sabinians advocated strict adherence to ancient rules of Roman law and resisted legal innovation. This conservative outlook reinforced Gaius's deep interest in the antiquities of Roman law.
In the 1950s, Polish-American sculptor Joseph Kiselewski was commissioned to create four marble reliefs over the gallery doorway at the Chambers of the U.S. House of Representatives in Washington D.C. Each relief is 28 inches in diameter, and one of the four depicts Gaius the Roman jurist.