Short answers, pulled from the story.
Papinian, full name Aemilius Papinianus, was a Roman jurist born around 142 CE in Emesa, of Syrian origin. He served as attorney general, master of petitions, and praetorian prefect under Emperor Septimius Severus, and was regarded as one of the most authoritative legal minds in ancient Rome.
Papinian was executed around 212 CE after Caracalla killed his own brother Geta and seized sole power over the Roman Empire. Papinian had been entrusted with both brothers by their dying father Severus, and his attempts to keep peace between them drew Caracalla's hatred. Caracalla ordered him beheaded, with his body dragged through the streets of Rome.
Papinian's principal works include the Quaestiones in 37 books, written before 198 CE, and the Responsa in 19 books, written between 204 CE and his death. He also wrote the Definitiones, De adulteriis, and a Greek manual on street and bridge commissioners called Αστυνόμικος. Much of his output has been lost.
The Law of Citations, passed in 426 CE, designated five Roman jurists whose recorded opinions were authoritative in court: Papinian, Gaius, Paulus, Modestinus, and Ulpian. When those jurists disagreed, Papinian's view was given precedence over the others.
Jacques Cujas, a 16th-century French jurist, wrote that "there was never such a great lawyer before, nor ever will be after him." Cujas was among the leading legal scholars of his era and his assessment reflected the lasting reverence Papinian commanded across centuries.
Third-year law students in ancient Rome were given the title "Papinianistae," meaning they were worthy to study Papinian. The designation reflected how highly his legal writings were regarded within Roman legal education.