Forzados alone could not fill the demand for galley rowers, despite the increasing number of crimes punishable by galley service and despite the increasing rate of convictions. Their numbers consequently came to be supplemented by slaves from several other sources. Many were Muslim prisoners of war, captured in naval engagements in the Mediterranean and in attacks on North African cities. Other ways for slaves to enter galley service was for forzados to purchase slaves who would substitute for them, or to provide money for such purchases. Government officials bought others, almost always Muslims, from private owners, frequently using the profits from the auctions of overage or disabled galley slaves. Slave owners, by selling or donating recalcitrant slaves to the royal officials for galley service, rid themselves of unsuitable slaves and perhaps ensured the loyalty of their remaining slaves, who no doubt hoped to avoid a similar fate.9 As an example, in 1603 the Spanish government paid don Diego López de Haro two hundred ducats as the price of two Turkish slaves whom he sent to the galleys.10 The government could confiscate privately owned slaves for galley service in times of heightened demand for galley rowers or at periods when private owners offered an insufficient number for donation or sale. In galley service, forzados could only work at the oars. Slaves might man the oars as well, but they could occupy other positions prohibited to the forzados, such as assistants of the guards and barbers and servants of the officers of the vessels.11
Two special categories existed among the slaves on the galleys. One group, the arráeces—usually the captains of Muslim pirate vessels—were held as slaves permanently. They had no hope of being sold away from the galleys or of being freed. The other group was slaves who were sentenced to the galleys after having been convicted of a crime. During the term of their sentence, they blended into the mass of the forzados. When their sentences expired, they did not attain their freedom, unlike the forzados. Their owners could reclaim them; if they did not, the slaves remained in galley service.12
Galleys became increasingly obsolete in the eighteenth century, and, even before they were abolished in 1748, the slaves and forzados no longer principally worked as rowers. The galleys usually remained in port and their involuntary crews worked in the naval yards. After the galleys were abolished, it was a natural step for the government officials to assign forzados and slaves to the naval arsenals. There they worked at various tasks of maintenance in the naval yards; their most arduous task was to operate the pumps that kept water out of the dry docks. Convicts continued to labor in the naval arsenals until 1818, but the last figures for slaves working in them come from 1786.13
Forzados and slaves also labored in public works and at the mercury mines at Almadén and the silver mines of Guadalcanal. Almadén was a particularly harsh environment. Toxic fumes from the furnaces produced mercury poisoning, and the heavy labor of operating the pumps debilitated the workers and left them vulnerable to infectious diseases. Some of the convicts even asked to be transferred to the galleys to escape the mines. By the early eighteenth century, slaves, usually purchased at low prices, came to be twice as common as convicts in the labor force. Improved technology in the eighteenth century, however, reduced the hazards of working there. It therefore became possible to recruit free workers, who ultimately replaced the slaves and forzados at Almadén.14
To sum up this section, slavery by birth was a constant throughout slavery’s history. Self-sale, debt slavery, and penal slavery did produce slaves, but not consistently and not in great numbers. None of these methods produced sufficient numbers of new slaves to meet demand. The capture and later enslavement of people born free provided the greatest number of slaves.
From Free to Slave
Captivity in war or in raids was the principal avenue to slavery for freeborn people. Both Romans and Visigoths enslaved captives. In the early years of the rise of Islam, when Muḥammad and his first followers secured control of the Arabian peninsula, the prisoners of war they captured, other Arabs, were enslaved if they were not ransomed. When the Muslims expanded beyond Arabia, the situation changed. By the time the Muslims took Spain, the possibilities of enslavement through war had declined sharply. Islamic religious tradition held that Jews and Christians were “people of the book,” fellow seekers after truth whose holy books governed their religious actions. As dhimmī, protected aliens, they could not be enslaved outright, although during the wars of expansion the victors often violated this prohibition. Free Muslims could not be enslaved legally, but occasional violations of this rule followed quashed revolts. There was no mass freeing of slaves in newly conquered areas, even if the slaves later embraced Islam, and the mere fact of conversion to Islam was not sufficient to free a slave.
The practice of slavery in the Christian kingdoms was changing by the late eleventh and twelfth centuries as the Christian reconquest gained momentum. More and more frequently, campaigns by Christians captured and held whole towns and cities with large Muslim populations. Alfonso VI’s seizure of the large city of Toledo in 1085 is perhaps the best example. No longer was it possible to carry out wholesale enslavements among the conquered population, even though some male prisoners—defeated combatants—were still enslaved. Rather, the remaining Muslims, the Mudejars, were allowed to remain and carry on their lives subject to the authority of the Christian rulers. Enslavement of unransomed captives continued. As one example of the numbers of slaves captured, after the late eleventh-century reconquest of Avila, some two hundred Muslim slaves were put to work in chains to build the town’s famous walls. After the significant Christian victory over the Muslims at Las Navas de Tolosa in 1212, several thousand defeated Muslim warriors entered the market as slaves. Later battles also brought still more slaves to the market: for example, the battle of Jerez de la Frontera in 1231.15
In the 1260s, the Muslim poet Abū al-Baqā’ al-Rundī lamented the fate of the Muslims who fell into the hands of the Christians after the conquest of Seville:
Yesterday they were kings in their own houses, but today they are slaves in the land of the infidel!
Thus, were you to see them perplexed, with no one to guide them, wearing the cloth of shame in its different shades,
And were you to behold their weeping when they are sold, the matter would strike fear into your heart, and sorrow would seize you.
Alas, many a mother and child have been parted as souls and bodies are separated!
And many a maiden fair as the sun when it rises, as though she were rubies and pearls,
Is led off to abomination against her will, while her eye is in tears and her heart is stunned.
The heart melts with sorrow at such [sights], if there is any Islam or belief in that heart!16
We can see how the process of captivity and enslavement developed in the conquest of the Balearic Islands. After King Jaume I the Conqueror took over Mallorca after hard fighting (1229–32), many members of the Muslim community fled, while others were enslaved. About the same time (1231), Jaume made a treaty with the Muslim population of Minorca, who accepted client status. The Muslims of Minorca adhered to the treaty until the 1280s, when they began a series of rebellions against the Aragonese. In response to the violations of the treaty, Alfons II subdued Minorca, treated the rebellious islanders in a punitive fashion, and enslaved the captives. The chronicler Muntaner reported that 40,000 captives were put on the slave market, although that figure is likely an exaggeration. Whatever their real numbers were, the captives were offered the possibility of being ransomed. Those