Complex sentence: Saint Cybi (in Welsh) or Saint Cuby (in Cornish) was a 6th century Cornish bishop, saint and, briefly, king, who worked largely in North Wales: his biography is recorded in two slightly variant medieval'lives'.
Split into simpler sentences: Saint Cybi (in Welsh) or Saint Cuby (in Cornish) was a 6th century Cornish bishop, saint and, briefly, king, who worked largely in North Wales. His biography is recorded in two slightly variant medieval'lives'.