In Spanish, double letter usage indicates a plural. For example, the U.S. (United States) is EE. UU., or E.E.U.U., or simply EEUU (Estados Unidos) in Spanish.
The Kingdom of Spain is a sovereign state largely located on the Iberian Peninsula in southwestern Europe. As a historic superpower with a story intertwining with many European and middle-eastern powers, and as key player in the history of religion and the Americas, Spain is full of historic importance.