Antonius was the village historian in Camelot.
Antonius's curiosity led him to allow the members of SG-1 into Merlin's library. He was fearful to do so, worrying that Meurik, the village leader, his fellow villagers, and most especially, his wife Livia, would find out about his escapades. Antonius was killed by the Black Knight (Merlin's Curse.) The technology was speculated to attack anyone and everything in the village, according to Dr. Daniel Jackson, however, Antonius did carry one of Merlin's books home with him, marking him a prime target. (SG1: "Camelot")