Mérida, city (1990 pop. 53,732), Badajoz prov., SW Spain, in Extremadura, on the Guadiana River. It is a rail hub and agricultural center producing textiles, leather, and cork. The colony Emerita Augusta, founded by the Romans in the 1st cent. B.C., it became the capital of Lusitania. Its Roman remains, among the most important in Spain, include a magnificent bridge, a triumphal arch, a theater with marble columns, an aqueduct, a temple, an imposing circus, and an amphitheater. Mérida was later the chief city of Visigothic Lusitania. It fell (713) to the Moors, under whom it prospered. Conquered (1228) by Alfonso IX of León, it was given to the Knights of Santiago but quickly declined.