This article offers a new historiographical overview of the military history of Spain in the early modern period, covering recent works published by English-speaking scholars as well as the latest studies by Spanish and Italian historians. Differences tend to focus on whether the rival paradigms of ‘decline’ or ‘resilience’ offer the better insights into the period after the end of Spanish military supremacy (c. 1648). A survey of recent work on this topic leads us to some very significant observations about factors underpinning power, such as a common or shared culture and identity, as well as the more obvious and traditional components of military and naval power. The nature of royal power and monarchy are analysed, as are the structure of the army and the construction of the state in Spain. The relationship between the state and civil society, and the debate about the militarization of Iberian society and the study of cultural and religious values, are also examined. On balance, recent literature leads us to a more positive assessment of the resilience of Spanish military power in the second half of the 17th century.