Among the many consequences of Spain's annexation of Portugal from 1580 to 1640 was an increase in the number of Portuguese authors writing in Spanish.
One can trace this practice as far back as the medieval period, although it was through Gil Vicente, Jorge de Montemayor, and others that Spanish-language texts entered the mainstream of literary expression in Portugal.
Proficiency in both languages gave Portuguese authors increased mobility throughout the empire.
For those with literary aspirati.
Purdue University Press Being portuguese in spanish: reimagining early modern iberian literature, 1580-1640, paperback/jonathan william wade
