The Marca Hispanica (Spanish Mark) were a series of buffer states set up Charlemagne to keep the Muslim Moors from advancing into the Frankish Empire.
The titled was first conferred upon Catalonia, at the start of the Reconquista, and indeed is sometimes used to mean this country alone. In its broader meaning, however, it refers to several former Spanish countries, of which Andorra is the sole surviving independent nation. As time passed, the counts of these countries were gaining independence from the imperial rule.