Close to the beginning
Cai is Arthur’s foster-brother. That is the useful starting point for reading him: a family relationship within a company organised for war.
A war-band can be described through its numbers, equipment and employment. Kinship adds another way to understand the people inside it. A familiar voice, an old obligation or a shared memory can carry a weight that a formal command cannot explain by itself.
A name in the older material
Cai also belongs to the Welsh legendary tradition. The archive’s file on Triad 21 offers a sourced starting point for that older reputation, alongside a spoiler-free discussion of the novel’s introduction to Arthur’s companions.
A question to carry
How might knowing someone before he becomes a leader change the way you hear his orders?