The Jews of Spain, being multilingual, urban, and literate, filled an economic niche in the predominantly agricultural economy and also played an important role in the circulation of goods and ideas from the Arabic- to the Latin-speaking world by way of Hebrew and the Iberian vernaculars. Over the centuries, Jews often found themselves in the middle of the two powers, serving as mediator and translator between them.

During the following three centuries, the Jewish population of the northern Iberian Peninsula had what could be described as a relatively prosperous period under the protection of the Christian kings, becoming involved in regional commerce, agriculture, and government administration. Castilian Jews were accused of exploiting Christians through their positions as tax collectors and administrators.

It is here that the Jews, as commercial agents with contacts with fellow Jews dispersed throughout the Mediterranean and along the trade routes, played a vital role in maintaining an economic lifeline between East and West. And being multilingual, with a command of early Spanish as well as Arabic and Hebrew, they moved easily across national boundaries. What differentiates the Sephardim from the Mudejars and explains their greater impact is that they were also widely employed in public offices as administrators of estates, lawyers, scribes, physicians, translators, emissaries, tax collectors, the same influential positions that they had earlier occupied under the Moors. And yet thanks to their expertise as administrators of noble estates and royal courts, or physicians to the kings, or diplomats, the Jews acquired power and influence beyond their numbers.

In its heyday, Spanish Jewry was one of the largest, most prosperous, and cultivated Jewish communities in the world. Despite centuries of unrivaled Jewish success, this “Golden Age” came to an end in 1492 with the promulgation of the “Alhambra Decree,” which presented the Jews with the options of conversion to Catholicism, exile, or death. This period of success is often associated with Jewish involvement in medicine, finance, administration and scholarship within Christian and Muslim polities on the Iberian Peninsula, although most Jews remained of modest means.

The Jews were protected by the Christian monarchs, for they made useful administrators of the new territories as well as tax collectors and facilitated contacts in Arabic. The development of urban life called for shopkeepers and administrators.

During the Middle Ages the position of tax-collector was often filled by Jews. Mention is made of Jewish tax-collectors in France as early as the sixth century. In Spain, Jews served as tax-farmers and receivers for the crown and for great nobles; until the regency of John I of Castile (1385) Jews held the position of tax-receivers in Portugal also. The higher Polish nobility, however, depended largely on the Jews for tax-collectors; until recently the Russian government also made use of Jewish tax-gatherers for the collection of taxes from the Jews.

Jewish officials were involved in key administrative tasks, such as tax collection and coinage. Jewish families were also active in trade and credit.

Christians and Jews in fourteenth- and fifteenth-century Castile relied on income from local taxes levied on commercial transactions. Jewish communities, in particular, were heavily involved in the farming and administration of indirect taxes on consumption, such as excises on wine, meat, and other goods. The article shows that Jewish tax-farmers and officials played a crucial role in the fiscal systems of late-medieval Castile, often acting as intermediaries between the crown, towns, and taxpayers.

The Umayyad Muslim conquerors of Spain were unusually tolerant of the Jewish and Christian minorities in Al-Andalusia, allowing them a great deal of autonomy which enabled them to religiously, academically, economically and artistically operate freely within the larger culture. This created one of the most productive symbiotic relationships in the Medieval world, also known as The Golden Age of Spain from the 8th to 11th centuries. Jews held significant positions in the government, economy, and academia. Prominent figures emerged during this time, such as Shmuel HaNagid, rabbi, poet, diplomat and commander of the Muslim army of Cordoba, Maimonides, the great rabbi, physician, philosopher, Judah Halevi influential scholar, poet and philosopher, and Hasdai ibn Shaprut, the physician and scholar.

In a study of the Híjar community, the author describes it as one of several Jewish communities in Aragon that possessed synagogues and communal institutions in the early fifteenth century. The article notes that the synagogue built in the first third of the fifteenth century attests to an organized community with the resources to construct and maintain such a building, implying the presence of merchants, artisans, and possibly professionals who supported communal life. While the focus is architectural, the broader context is that Jewish communities in Aragon remained active up to the expulsion of 1492.

The Jewish moneylenders, tax collectors, and advisers became quite important. As the community grew so did their social, cultural, and political influence. The Benveniste family were royal tax collectors, treasurers, physicians, administrators, and advisors to the kings of Aragon and Castile between the 12th and 13th centuries. In Aragon and Barcelona, they became important royal advisors and tax collectors, frequently entrusted with key financial and administrative responsibilities.

This popular history notes that "Toledo became not only the Jewish capital but also home to chief rabbis, Talmudists, scholars, and financiers" during the period often termed a golden age of Jewish life in Spain. It mentions leading figures recognized as physicians and translators, including Judah ben Tibon, "named the Father of Translation," whose work as a translator of Arabic scientific texts facilitated the transmission of scientific advances to Europe. The article also situates prominent Jewish physicians such as Nahmanides within Catalonia’s Jewish quarters, indicating the presence of medical practitioners and scholars within Iberian Jewish communities.

In medieval Spain, Jews often served as tax collectors for kings, nobles and towns, and as such they occupied a crucial yet precarious role within Christian society. “It was a perfect scapegoat – no one likes the person collecting taxes,” notes historian Yom Tov Assis. Jewish tax collectors could become wealthy and influential, but their position exposed them to popular resentment and violence, especially in times of fiscal crisis.

An AskHistorians response explains that in the later Middle Ages, including the decades before 1492, Jews in Castile and Aragon were heavily regulated but continued to serve as tax farmers and royal fiscal agents. The poster notes that the Crown relied on Jewish tax collectors and financiers for revenue administration, which contributed to anti-Jewish sentiment and demands for their expulsion or forced conversion. The answer emphasizes that although Jews were important in these specific roles, they formed a small minority of the kingdom’s population and most Jews were modest artisans or traders rather than high officials.

Second, Jews held positions in banking and were subject to fewer regulations involving loans. The economic reasons behind why the Jews were targeted were the following: first, medieval Spanish Jews emphasized education, which led to better paying professional occupations. Second, Jews held positions in banking and were subject to fewer regulations involving loans. Spanish Catholics believed that the Jews had too much power and money, leading to resentment before the expulsion of 1492.

Jewish doctors, lawyers, artisans, and professionals flooded neighboring countries, enriching their cultures and economies instead of Spain’s. Moreover, prominent Jewish thought centers in cities like Toledo, a major hub for Jewish life, were extinguished. This description, based on a 1492 letter regarding Jewish property in Spain, highlights the loss of skilled Jewish professionals following the expulsion, implying that Jews had occupied a range of professional roles in late-medieval Spain.

Among the crucial events that contributed to the Sephardic medical diaspora were the setting up of a new Inquisition in Spain (1478) and the gradual implementation from the mid-fifteenth century of statutes of "purity of blood" that legalized the social exclusion of new Christians by blocking or making very difficult their access to any public position or high honour. These measures affected converso physicians and other professionals of Jewish origin, forcing many to emigrate and continue their medical careers abroad, as in the case of Rodrigo de Castro, a prominent physician in Hamburg of Portuguese converso background.

These communities operated as fiscal and administrative units under royal protection, with Jewish law functioning within this acknowledged corporate framework. While Jews could still rebuild their institutions and engage in economic activities, the normative vision of Christian society was evolving toward clearer boundaries that excluded Jews. … Most Jews in late medieval Spain were poor artisans and small-scale merchants living on the edge of poverty, while only a small number of wealthy and powerful Jews served as major moneylenders or high officials, despite Christian perceptions of Jewish economic dominance.

The services of Jewish scientists, doctors, traders ... He employed wealthy Jews—Samuel Abravanel and others—as financial councilors and tax collectors. ... On account of their talent and wealth ... the converts and Marranos gained considerable influence and filled important government offices.

Drawing on historical scholarship, this background note explains that in late‑medieval Castile and Aragon, Jews and later conversos were prominent among royal tax farmers, financial administrators, and some court physicians, but they were numerically small compared to the overall population. Anti‑Jewish polemic often portrayed Jews as disproportionately powerful in these essential professions, especially in tax collection and royal finance, even though most Jews worked as artisans, small traders, or in other modest occupations. This perception of disproportionate influence contributed to social tensions and to measures restricting Jewish practice of medicine and other trades in the 15th century.

According to Jewish legend, Jews had lived in Spain since the destruction of the first Temple in Jerusalem in the fifth century B.C.E. Yet ... in medicine, commerce and government.

The Bonaventura family was prominent in Monforte's Jewish community in the period before the expulsion of Spain's Jews in 1492. At the time, Jews in various towns of Castile and Aragon engaged in trades, artisanal work, small-scale commerce and occasionally in administrative or financial roles linked to royal or noble households. Localized genealogical evidence indicates that Jewish communities contained both modest artisans and a smaller number of families involved in more prestigious professions.

Most Jews were poor and led ... many did turn to money lending especially in the later Middle Ages as they were pushed out of other professions, but the primary Jewish occupation in medieval Spain ... was that of artisan. ... They were also involved heavily in small-scale commerce and trade.

In addition to contributions of original work, the Sephardim were active as translators. Greek texts were rendered into Arabic, Arabic into Hebrew, Hebrew and Arabic into Latin and all combinations of vice versa occurred. ... Iberian Jews were instrumental in bringing the fields of science and philosophy into the rest of Europe.