The Mesta (Spanish Honrado Concejo de la Mesta, Honoured Council of the Mesta) was a powerful association of sheep holders in Castile, and one of the most important guilds in medieval Europe. It was created in 1273.
Sheep farming grew out of the insecurity of the border lands between Islamic and Christian Spain, considered far too unstable for arable farming. This no-man’s-land often measured as wide as 100 kilometres. Disputes were settled by local agreements, which eventually developed, as the Reconquista progressed, to the Mesta. Huge flocks of transhumant sheep migrated every year from the pastures of Extremadura and Andalusia to Castile and back according to the season. As arable farming expanded it became necessary to govern this lucrative traffic with routes along which livestock was permitted to travel and graze (cañadas, cuerdas, cordeles...). Each type of path stipulated the width permitted. see also Cañadas Reales
• cordal: cañada measuring 45 varas around 40 metres
• encañada : drover's road as it passes through a gorge
• carrerada (Cat.); cañada
• valgada (Gal.); cañada
The importance of the Mesta to the economy of Castile is reflected in the fact that members enjoyed many privileges such as exemption from military service. Even today, the cañadas (drover’s roads or traditional rights-of-ways for sheep) are, in theory at least, legally protected from occupation and barring, though this law has been much flaunted in recent decades.
The Mesta is often seen as the first, and most powerful, agricultural union in mediaeval Europe. Huge profits were made in exporting Castile’s principal product to the rest of Europe. It was finally abolished in 1836, as competition from other areas and political factors in Spain had made the association anachronistic.
The Mesta was one of the biggest causes of deforestation as hundreds of thousands of sheep would traipse across the Peninsula every year, grazing and being fed with additional fodder.
The most important drover’s paths were the Cañadas Reales, each with many tributary paths:
• Cañada leonesa, León-Extremadura.
• Cañada segoviana, Logroño-Valle del Guadalquivir.
• Cañada manchega Cuenca-Guadalquivir.
Mesta comes from the Latin “animalia mixta” meaning "mixed animals".- beasts without a known owner. When shepherds met up to so did their sheep. When the council was eventually established, it was also called mesta. The word mustang (mixed) comes form the same source.
• " Concejo de la Mesta. (Wikipedia Spanish)