Cyrus is the second son of Duke Parris of Amber's House Chantris, making him the fourth child. He is in charge of Chantris's merchant fleet and from an early age sailed the longest and most unusual trade routes. It was the "most unusual" part that got him in trouble repeatedly. It is also the part that led him to Pathi.
Cyrus's ship had been lost for nearly two weeks when he and the navigator struck out in a smaller craft in an attempt to find help. Several days later, the two men had found nothing and were on the verge of returning to the rest of the men when they were swept away by a sudden storm. The navigator was lost during the storm and Cyrus was found drifting on what was left of his boat by Kynan.
Cyrus was nursed back to health in Pathi and despite the fact that he was kept away from anything sensitive or secret, his skill with languages and his natural curiosity allowed him to leave the city with more knowledge than the average outsider. Chantris is a House of secrets which means that Cyrus guards what he learned in Pathi like a custos guards his charge.