Philip III of Spain issues the decree of the "Expulsion of the Moriscos".

The Expulsion of the Moriscos (Spanish: Expulsin de los moriscos) was decreed by King Philip III of Spain on April 9, 1609. The Moriscos were descendants of Spain's Muslim population who had been forced to convert to Christianity. Since the Spanish were fighting wars in the Americas, feeling threatened by the Turks raiding along the Spanish coast and by two Morisco revolts in the century since Islam was outlawed in Spain, it seems that the expulsions were a reaction to an internal problem of the stretched Spanish Empire. Between 1609 through 1614, the Crown systematically expelled Moriscos through a number of decrees affecting Spain's various kingdoms, with varying levels of success.

Although initial estimates of the number expelled such as those of Henri Lapeyre range between 275,000 and 300,000 Moriscos (or 4% of the total Spanish population), the extent and actual success of the expulsion order in purging Spain of its Moriscos has been increasingly challenged by modern historians, starting with the seminal studies carried out by Franois Martinez (1999) and Trevor J. Dadson (2007). Dadson estimates that, out of a total Morisco population of 500,000, a figure accepted by many, around 40% avoided expulsion altogether and tens of thousands of those expelled managed to return.The places where the expulsion was particularly successful were the eastern Kingdom of Valencia, where Muslims represented the bulk of the peasantry and ethnic tension with the Christian, Catalan-speaking middle class was high; as a result, this region implemented the expulsion most severely and successfully, leading to the economic collapse and depopulation of much of its territory, worsened by the bubonic plague which hit Valencia only a few years later. The Kingdom of Aragon was, after Valencia, the part of the peninsula with the largest rate of expelled Moriscos and suffered the consequences as disastrously as Valencia, according to Henri Lapeyre.Of those permanently expelled, the majority eventually settled in the Barbary Coast (Maghreb), with around 30,000 to 75,000 people ultimately returning to Spain. Those who avoided expulsion or who managed to return to Spain merged into the dominant culture. The last mass prosecution against Moriscos for crypto-Islamic practices took place in Granada in 1727, with most of those convicted receiving relatively light sentences. By the end of the 18th century, indigenous Islam and Morisco identity were considered to have been extinguished in Spain.

Philip III (Spanish: Felipe; 14 April 1578 – 31 March 1621) was King of Spain. He was also, as Philip II, King of Portugal, Naples, Sicily and Sardinia and Duke of Milan from 1598 until his death in 1621.

A member of the House of Habsburg, Philip III was born in Madrid to King Philip II of Spain and his fourth wife and niece Anna, the daughter of Holy Roman Emperor Maximilian II and Maria of Spain. Philip III later married his cousin Margaret of Austria, sister of Ferdinand II, Holy Roman Emperor.

Although also known in Spain as Philip the Pious, Philip's political reputation abroad has been largely negative. Historians C. V. Wedgwood, R. Stradling and J. H. Elliott have described him, respectively, as an "undistinguished and insignificant man," a "miserable monarch," and a "pallid, anonymous creature, whose only virtue appeared to reside in a total absence of vice." In particular, Philip's reliance on his corrupt chief minister, the Duke of Lerma, drew much criticism at the time and afterwards. For many, the decline of Spain can be dated to the economic difficulties that set in during the early years of his reign. Nonetheless, as the ruler of the Spanish Empire at its height and as the king who achieved a temporary peace with the Dutch (1609–1621) and brought Spain into the Thirty Years' War (1618–1648) through an (initially) extremely successful campaign, Philip's reign remains a critical period in Spanish history.