The Heimurinn Chronicles
Reavings or Cattle-Raids are common in the Highlands. Reaving had been a rite of passage. Reavers were young men who took/stole livestock from neighboring clans. The livestock taken was often recovered by payment of tascal (information money) and guarantee of no prosecution.
To go on a reaving was to go out from clan lands usually to a rival clan, usually to steal cattle or other resources. Typically done by young men to prove their martial ability. Reavings that headed into the North Aethlund were especially bothersome to the Earls that depended on the cattle to pay taxes to the King.