The Spanish Legion was officially created on January 28, 1920, at the behest of General José Millán Astray, a key figure in the Spanish military. Positioned to bolster Spain's military presence in Morocco, this new corps drew heavily from the concept of foreign legions, welcoming volunteers from several nations. Its foundation coincided with increased tensions and conflicts in the Rif region of northern Morocco, where Spanish interests were under threat from local Berber tribes. The establishment of the Legion represented a response to these colonial challenges, aiming to create a highly disciplined and motivated unit capable of undertaking difficult military operations.

The Legion quickly became famous for its unique camaraderie and camaraderie, attracting not only Spaniards but also foreign volunteers, notably from countries like France and Italy. This melting pot of soldiers contributed to its diverse and robust character, setting a precedent for future military units in Spain. The Legion was distinct not only for its operational effectiveness but also for its colorful traditions, including elaborate ceremonies and a motto that reflected its fearless ethos—“¡Viva la muerte!”—which translates to “Long live death.” This fierce motto embodied the Legion's spirit, emphasizing loyalty and courage in the face of adversity.

As the years progressed, the Spanish Legion played an integral role in several military campaigns, from the Rif War to the Spanish Civil War, further cementing its reputation in both domestic and international arenas. The culture and identity fostered within the Legion would influence Spanish military policy and global perception of Spain's military capabilities well into the 20th century. Its legacy includes a complex relationship with Spain’s military history, marked by both valor and controversy, as it engaged in conflict not just in Spain but across various territories, shaping the nation’s colonial and post-colonial military narrative.