The study of prisoners of war in Spain continues to be far from the historiographical spotlight. However, 17th century soldiers were constantly captured in acts of war. Hundreds, even thousands of them were captured during battles, sieges and skirmishes, gaining a ubiquitous presence in the war-torn landscape of Europe. The ever-growing size of the armies, the continental scale of conflicts and the international nature of those armies and states led to an exponential growth in the number of prisoners of war. The armies of the Hispanic Monarchy were deployed throughout the many war fronts in which Spain was present, such as Catalonia, Portugal, or the Spanish Netherlands. Hence the need to implement a comprehensive approach considering the whole scope of the Hispanic Monarchy in what relates to prisoners of war, rather than focusing solely on a single territory or specific conflict, in order to provide a longlasting overview. Firstly, the process of becoming a prisoner of war will be examined through the lens of the contemporary war culture. In other words, the evolution in the treatment of those prisoners and their ever-growing value when it came to ransoms, prisoner exchanges or even their potential recruitment by the same armies that held them as captives. Next, we will delve into the personal experiences of those prisoners, who amounted to more than 10% of Spain's soldiers. To do so, both first-hand testimonies from soldiers held captive and administrative documents by the system of councils of the Spanish Monarchy will be referenced. These sources allow us to delve into two other essential milestones in the life of prisoners of war: their living conditions, their rights and the problematics they faced in captivity, as well as their lives once released. By doing so, the whole journey of the prisoners of war, from their capture to their liberation -focusing on some specific problems due to length constraints to develop them all- will be comprehensively mapped out. This would, in turn, allow us to assess the phenomenon in a general level while at the same time continuing to work on this line of research, which remains mostly unexplored.