Short answers, pulled from the story.
Aurelius Hermogenianus served as magister libellorum to Emperor Diocletian during the early fourth century. This official title meant he drafted responses to private petitions submitted to the imperial court.
Most of this work dates from the years 293 and 294 which were the peak years of the first tetrarchy under Diocletian, Maximian Augusti, and Constantius and Galerius Caesars. The arrangement followed a chronological order based on when each constitution was issued.
Most experts favor a middle ground of 69 titles supported by Krueger, Rotondi, Sperandio, and Corcoron. Haenel proposed a minimum of 18 titles while Cenderelli argued for as many as 147.
A brief section survives on a late antique papyrus from Egypt now held at the Pierpont Morgan Library. Copies of the full version remained exploited between the sixth and ninth centuries only in Merovingian and Frankish Gaul within two specific manuscripts known as Codd. Parisini regii 4414 and 4415.
An abridged version incorporated in the Breviary of Alaric promulgated in 506 explicitly superseded the original full text throughout Visigothic Gaul and Spain. By the mid sixth century the original text had been consigned to history over most of the Mediterranean world due to its integration into Justinian's framework.