The privileges of protection and immunity were a social and political reality common to European medieval kingdoms. In Iberian Peninsula, «coto» or «acotamiento» privileges played a main role in royal politics of the kingdom of León to preserve the royal jurisdiction in all territory and abandon the visigothic administrative model. In order to understand this role, it's essential to clarify the chronology, when monarchs used these privileges, and in which administrative context. This paper aims to offer a systematic study about their development, use and disuse; their main characteristics and their clauses evolution. To get it a database with all Galicia's published privileges, and so many unpublished, has been created. [ABSTRACT FROM AUTHOR]