Colonel Horyse was the commanding officer of the Northern Perimeter Reconnaissance Unit at the time of Sabriel. He has pale blue eyes that are described as having a "mixture of harshness and compassion". True to this, he was a good leader of his soldiers, showing sound knowledge of the dangers of the Perimeter as well as a sense of humour. His men duly follow his orders, suggesting that he was well respected. In chapter 25 of Sabriel, one of the corporals at the Perimeter even tells him a joke, so Horyse was probably an approachable officer as opposed to one who looked down on lower ranks.