Azemmour was the last important Portuguese conquest in the Maghreb, a strategic stage for the expansion of the Crown between the fifteenth and sixteenth centuries. Portuguese presence here, from 1513 to 1542, would irreversibly influence the town’s image, dimension, and limits, deriving from a drastic downsizing procedure. This technique was joined by important phases of military architecture experiments as its defences would play a key role in the early 1500s renovation that all the Portuguese North Africa possessions were witnessing.

The occupation of Azemmour happened at the same time as changes in taste and architectural needs were being revised by novel warfare technologies and early modern ideologies in Europe. Framed within a period of transition, military architecture here requires a cross-disciplinary study. Thus, historical sources were complemented by a thorough architectural survey and field work to provide plans and 3D models for analysis.

This chapter seeks the original drawing intentions by royal masters Diogo and Francisco de Arruda in order to look into the revolutionary concepts associated with the construction of a Manueline fortification. Many times sieged by a hostile hinterland where walls and bastions were, in fact, the borders of sovereignty, defensive structures need to be measured for their geometries and fire capacity or range. By determining the resilience of medieval rhetorical patterns with highly innovative proto-bastioned design, the influence of Francesco di Giorgio Martini’s studies to the work of the Arruda can be pointed out at a time when theorization began to circulate in Europe.

Partly ruined, partly renewed, the Azemmouri military built heritage is central to understanding the transitional architectural style between the Late Middle Ages and the early modern period, within a broad regional laboratorial experience in the Maghreb at the same time as when Portugal’s overseas empire was at the centre of science experimentation and the diffusion of knowledge in the field.