6 percent of the expected revenue, to the man who would physically collect the tax for him, leaving 4 percent for other expenses, such as bookkeeping materials.6 The 70 percent rule can also be checked against data from 1458, the only year for which both the tax farmer’s bid and the tax collection register have been preserved.7 In that year, Gregorio de Cassana bid 900 lire for the half-florin tax. The 70 percent rule suggests that Cassana expected 1,286 lire in revenue from a population of 1,582 slaves. In the 1458 collection register, I counted 2,025 slaves (yielding 1,645 lire, 6 soldi, 3 denari in revenue), and Domenico Gioffrè counted 2,059 slaves (yielding 1,672 lire, 18 soldi, 9 denari in revenue). In this case, the 70 percent rule was too generous: Cassana’s bid was only 54 to 55 percent of the revenue he collected. The actual slave population of Genoa in 1458 would have been higher still, because the Fieschi family and the Spinolas of Luccoli were exempt from the half-florin tax in 1458. In the following discussion, therefore, it should be assumed that estimates of the Genoese slave population are rough and more likely to be underestimates than overestimates. Figure 1 shows the winning bids for the half-florin tax between 1381 and 1472.8
Figure 1. The Half-Florin Tax on Slave Possession in Genoa.
(Gioffrè, Il mercato, 69–70; Balard, La Romanie, 2:816; ASG, CdSG, N.185,15002, N.185,15006, N.185,15072.)
Analyses of these data have tended to focus on demand rather than supply. The apparent peak in the late fourteenth century (about 7,223 slaves in 1381) is often linked to the Black Death: slaves could have alleviated the sudden labor shortage, and the threat of slave labor could have been used to coerce free servants into accepting lower wages.9 But because the data set begins in 1381, three decades after the first plague outbreak and two decades after the second outbreak, it is impossible say exactly what the effects were. There is no pre-plague baseline against which to measure 7,223 slaves and decide whether that figure is low or high. Moreover, it is impossible to tell whether any effects of plague on the slave population should be attributed to the first or second outbreak. A close examination of wills, merchant letters, Senate decisions, and guild statutes in Venice has yielded no evidence for change in either the number of slaves or the kinds of labor they performed as a result of the Black Death.10 Major plague outbreaks recurred in 1421, 1430, and 1436. Those correlate with dips in Figure 1, as plague deaths reduced the number of slaves.11 After 1430 and 1436, the slave population rebounded to its previous level as masters replaced those who had died. After the 1421 outbreak, though, the slave population only reached 75 percent of its previous level.
Other factors may have affected the slave population of Genoa. In the late fourteenth century, Genoa came under the rule of France. Difficulties in tax collection during the transition may explain the decline in half-florin tax bids between 1380 and 1400.12 In that case, however, bids should have returned to higher levels after the transition. No demand-based explanation has been offered for the peaks in 1417 (3,451 slaves) and 1440–1442 (3,049 slaves); factors affecting supply are discussed in Chapter 5. Overall, it seems that slaves made up 1 to 2 percent of the total Genoese population in the thirteenth century and 4 to 5 percent in the fifteenth century.13
Venetian and Mamluk records do not offer data comparable to Genoa’s half-florin tax. While Venice also instituted a three lire tax on slave possession in 1379 to fund its part in the Chioggia war, no records have survived.14 What remains is anecdotal evidence. The Senate received complaints about a slave shortage in 1459, which matches the Genoese data.15 In 1483, a Swiss pilgrim reported that Venice had three thousand slaves, about 2.5 percent of its total population.16 The Mamluks did not tax slave possession, nor were slaves included in the poll tax (jizya) paid by non-Muslim subjects.17 No travelers tried to estimate the slave population of Cairo, much less the entire Mamluk kingdom. Modern scholars have noted shrinking slave retinues (mamluks, concubines, domestic slaves, and slave musicians) in the late fourteenth and early fifteenth centuries.18 This corresponds to the marked decline in Figure 1 from 1381 into the early 1400s.
Another method of counting the slave population is by household. The bourgeois style of service described by Dennis Romano, in which one household had two or three female servants, was the norm in late medieval Italy.19 The best evidence for this pattern again comes from Genoa’s half-florin tax. In 1458, the half-florin tax was collected by household. As shown in Table 1, 95 percent of households who paid the tax had one or two slaves.20 None had more than six. This statistical picture is fleshed out by letters between the Genoese merchant Giovanni da Pontremoli and his family during the same year.21 Seven slaves are mentioned in the letters, but only two belonged to Giovanni.
Table 1. Number of Slaves per Household in Genoa, 1458
| No. of slaves per household | No. of households | Percentage of households |
| 1 | 1,143 | 74 |
| 2 | 330 | 21 |
| 3 | 57 | 4 |
| 4–6 | 12 | 1 |
Source: ASG, CdSG, N.185,01009.
Evidence from wills indicates a similar pattern in Venice. The famous traveler Marco Polo manumitted one slave in his will in 1324, and the Venetian painter Nicoletto Semitecolo also manumitted one slave in 1386.22 Panthaleo Iustiniano, a procurator of S. Marco, manumitted three slaves in 1393.23 Madalutia, the wife of Bernardo Aymo, manumitted two slaves in 1410.24 Andrea Barbarigo, a fifteenth-century patrician known for frugality, had two slave women in his household and one rented out.25 Giosafat Barbaro manumitted one slave in 1493.26 At the upper end of the spectrum, the apothecary Nascimbene de Ferraria mentioned six slaves in his will, but only four were present in his household.27
The number of slaves per household in the Mamluk sultanate ranged more widely. ‘Abd al-Laṭīf ibn ‘Abd al-Muḥsin al-Subkī boasted that he had gone through more than a thousand slave women, but elite civilian households more normally counted their slaves in the dozens.28 At lower social levels and after slave retinues shrank in the late fourteenth century, Mamluk civilian households resembled Italian ones. The households represented in a cache of fourteenth-century documents from Jerusalem had no more than four slaves.29 Ibn Ṭawq, a professional witness (shāhid) in Syria, owned two slave women.30 In Damascus, the estate of a private secretary of the sultan (kātib sirr) included five slaves, and a judge’s estate had four.31 A study of Syrian amirs in the late fifteenth and early sixteenth centuries found that none had more than one umm walad.32
Military households tended to have more slaves. Each amir commanded a unit composed of both mamluks and free horsemen.33 The size of the unit depended on the amir’s rank: an amīr mī’a muqaddam alf could have one hundred mamluks, an amīr arba’īn or amīr ṭablakhāna could have forty, an amīr ‘ashara could have ten or twenty, and an amīr khamsa could have five. Since the Mamluk army was theoretically composed of twenty-four amirs of one hundred, forty amirs ṭablakhāna, twenty amirs of twenty, fifty amirs of ten, and thirty amirs of five, there should have been a total of 26,650
