Justinian Code
From Memory Alpha, the free Star Trek reference.
The Justinian Code (also called the Code of Justinian) was a compilation of Roman and Byzantine laws overseen by Byzantine Emperor Justinian the First (a European political leader on Earth) during the 6th century. The Code was one of the legal authorities cited by defense attorney Samuel T. Cogley at Captain Kirk's trial for negligent homicide in 2267. (TOS: "Court Martial")
