Complex sentence: Claudius took a liking to him until Valentinus tried to lead Claudius to Jesus, whereupon Claudius refused and condemned Valentinus to death, commanding that Valentinus either renounce his faith or he would be beaten with clubs, and beheaded.
Split into simpler sentences: Claudius took a liking to him until Valentinus tried to lead Claudius to Jesus, whereupon Claudius refused and condemned Valentinus to death. Commanding that Valentinus either renounce his faith or he would be beaten with clubs, and beheaded.