Mardrid is the capital and largest city of Spain. At present, the population of the entirety of Madrid, central and suburbs, is approximately 5.84 million, making it the third-most populous municipality in the European Union. Madrid is known for preserving much of its historical look and feel, while boasting a modern infrastructure.
In an alternate where 80% of European population had been killed during the 14th century's Great Black Deaths, Madrid was a large, prosperous pre-industrial Muslim city of half a million people. Annette Klein felt the city resembled the Spanish mission architecture of her home timeline's California. Annette and Jacques were sold into slavery in Muslim Madrid and transported to another Madrid in which an illegal slave ring had conquered a territory belonging to both descendants of the Basques and Carthaginians. Annette was finally able to escape that alternate and arrive in the Madrid of her own timeline, a prosperous and bustling city of the European Union.
While in Home Madrid, Annette noticed that a monument to the 2004 terrorist attack had fallen into a state of disrepair.
Madrid remained in Republican hands for the first years of the Spanish Civil War. Nationalist leader José Sanjurjo did have the opportunity to take Madrid in 1936. He instead opted to relieve the forces of José Moscardó Ituarte at the Alcázar de Toledo instead. In October 1936, General Emilio Mola drove on Madrid with four columns, claiming a fifth column was inside the city ready to aid the Nationalist cause. This proved incorrect: the four columns didn't take the city, and the "fifth" inside provided no help. The Republicans massacred every Nationalist they could find.
In March 1939, Sanjurjo, flush with success after the Fall of Gibraltar, decided now was the time to take Madrid. Republican leaders decided to send the battle hardened Abraham Lincoln Brigade to help defend against the attack. Initially, the Nationalists gained some momentum, taking the University City District within a few weeks. However, they could not get into Madrid proper. The Republicans succeeded in pushing the Nationalists out of University City by the middle of the summer. The Nationalists maintained the offensive on Madrid for the remainder of the year, and into the next, but the line outside Madrid continued to hold on into 1940. Things looked particularly bleak for the Republic after the "big switch" of Summer of 1940 saw Britain and France align with Germany and cease supplying the Spanish Republic; however Germany was not in a position to help the Nationalists much more than they had been.
In the end, Britain and France's alliance was over at the end of 1941. This was the last threat to Madrid. The Republic was able to keep Madrid until its final victory in 1944.