In medieval times, before the unification of Castile, León and Grenada by Ferdinand and Isabella, the town of Uclés in eastern Castile held great strategic importance to both Christian and Moorish leaders.
First, Uclés sat on a high plateau called the Meseta. All frontier towns littering the landscape were cannon fodder, so to speak, in that they staunchly protected more populated cities such as Toledo and Madrid. Small communities maintained a standard compliment of walls and fortifications, with each and every person charged with defending the sanctity of Spanish Christendom from the heathens to the south. Despite their best attempts, the citizens of Uclés were unable to prevent conquest and lengthy periods of occupation by the Almohad forces. The small city flipped back and forth between Christian and Moorish control for more than two centuries.
What set Uclés apart from its neighboring towns was that it served as headquarters for the Order of Santiago, a unique order of warrior monks. These brothers could retain their property, bear arms, and even get married--unusual concessions granted by Alexander III in 1171 as a means of attracting more able-bodied men to the Order and to defend Christian possessions. Being able to retain these would-be soldiers of God had a secondary advantage in that their commitment to serving the Order also meant they weren't out pillaging the countryside. Aimless bachelors were almost as dangerous as Moorish raiders.
My January 2010 release, SCOUNDREL'S KISS, is partly set in Uclés. Here's a description:
Their shadows stretched long and reached the defenses well in advance. Guards along the saw-toothed stone wall wore identical white robes adorned with the red Cross of Santiago. They nodded a silent greeting but kept the gates locked, lances at the ready. Brick filigree patterned the ramparts atop the two west-facing towers, but the fortress's other features seemed designed to intimidate, all hulking, block construction, rectangular windows and steep stairs. No softness and no weakness.
But it wasn't only the Moors who threatened Uclés. A rival branch of the Order of Santiago, housed in León in the Kingdom of León, also claimed to sit at the head of the Order. Violence erupted between the factions when they weren't busy fending off Almohad. For a time, even, two rival grand masters claimed leadership. Only once Ferdinand III united Castile and León in 1230 did the Order decide on a mutual grand master and move permanently to Uclés.
Upon the foundation of the Archivo Histórico Nacional de Madrid in 1869, the Order turned is lush archives over to the state. By then, the violence in Uclés was done, its importance to the early formation of Spain and the protection of Christianity against its rivals was long past.