In a financial and industrial point of view the Mudéjares formed a most valuable portion of the population. The revenues derived from them were among the most reliable resources of the State; assignments on them were frequently used as the safest and most convenient form of securing appanages and dowries and incomes for prelates and religious establishments.[198] To the nobles on whose lands they were settled they were almost indispensable, for they were skilful agriculturists and the results of their indefatigable labors brought returns which could be realized in no other way. That they should be relentlessly exploited was a matter of course. A fuero granted, in 1371, by the Almirante Ambrosio de Bocanegra to his Mudéjares of Palma del Rio, not only specifies their dues and taxes, but prescribes that they shall bake in the seignorial oven and bathe in the seignorial bath and purchase their necessaries in the seignorial shops.[199] They were not only admirable husbandmen and artificers, but distinguished themselves in the higher regions of science and art. As physicians they ranked with the Jews, and when, in 1345, Ferrant Rodríguez, Prior of the Order of Santiago, built the Church of Our Lady of Uclés, he assembled "Moorish masters" and good Christian stone-masons, who constructed it of stone and mortar.[200] The industry of Spain was to a great extent in their hands. To them the land owed the introduction of the sugar-cane, cotton, silk, the fig, the orange and the almond. Their system of irrigation, still maintained to the present time, was elaborately perfect, and they had built highways and canals to facilitate intercourse and transportation. Valencia, which was densely populated by Mudéjares, was regarded as one of the richest provinces in Europe, producing largely of sugar, oil and wine. In manufacturing skill they were no less distinguished. Their fabrics of silk and cotton and linen and wool were exquisite; their potteries and porcelains were models for the workmen of the rest of Europe; their leather-work was unsurpassed; their manufactures of metals were eagerly sought in distant lands, while their architecture manifests their delicate skill and artistic taste. Marriages were arranged for girls at 11 and boys at 12; dowries were of little account, for a bed and a few coins were deemed sufficient where all were industrious and self-supporting, and their rapid increase, like evil weeds, was a subject of complaint to their Castilian detractors. Ingenious and laborious, sober and thrifty, a dense population found livelihood in innumerable trades, in which men, women and children all labored, producing wealth for themselves and prosperity for the land. In commerce they were equally successful; they were slaves to their word, their reputation for probity and honor was universal, and their standing as merchants was proverbial. There was no beggary among them and quarrels