Many of the Castillian merino flocks were owned by nobility or the church, although Alfonso X realised that granting the urban elites of the towns of Old Castile and León transhumant rights to would create an additional source of royal income and counteract the power of the privileged orders During the late 15th, 16th and early 17th century, two-thirds of the sheep migrating annually were held in flocks of less than 100 sheep and very few flocks exceeded 1,000 sheep. By the 18th century, there were fewer small owners, and several owners held flocks of more than 20,000 sheep, but owners of small to moderately-sized flocks remained, and the Mesta was never simply a combination of large owners.
