It is scarce worth while to multiply trivial details like these to indicate how efficient a political agency the Inquisition had become under the Restoration. Its activity in this direction continued until the end and when, in the Revolution of 1820 at Seville, on March 10th, the doors of the secret prison were thrown open, the three prisoners liberated were political.[568] * * * * * Besides these direct political services, the Inquisition was sometimes called upon by the State to aid in enforcing secular laws, when the civil organization found itself unequal to the duty. The most conspicuous instance of this is found in the somewhat incongruous matter of preventing the export of horses. [Sidenote: _EXPORTATION OF HORSES_] From a very early period this was regarded with great jealousy. From the twelfth century onward, the Córtes of Leon and Castile, in their petitions, constantly asked that the prohibition should be enforced and, at those of Burgos in 1338, Alfonso XI decreed death and confiscation for it, even if the offenders were hidalgos, a ferocious provision which was renewed by Ferdinand and Isabella in 1499.[569] Aragon, which lay between Castile and France, suffered from this embargo. The Córtes of Monzon, in 1528, petitioned Charles V for the pardon of certain citizens who had drawn horses from Castile and were condemned to death and other penalties, to which Charles replied that he would not pardon those who had carried horses to France; as for those who had merely taken them to Aragon, if they could be pointed out, he would grant them pardon. Another complaint of the Córtes indicates the rigid methods adopted to prevent evasions. If an Aragonese went to Castile on business, he was allowed to remain ninety days; if he exceeded the limit, on his return his horse was seized at the frontier, even though at the same place by which he had entered.[570] Severe as were these measures, they were ineffective. Contraband trade of all kinds flourished in the wild mountain districts along the French frontier, and the prohibition respecting a beast of burden, which transported itself, was notoriously difficult of enforcement.