Introduction: Divergent Experiences in Religious Empires
From the early medieval period through to the early modern era, Jewish communities lived under two dominant civilisations: Islamic caliphates and Christian kingdoms. These overlapping yet distinct religious empires profoundly shaped Jewish social, economic, intellectual, and religious life. While both contexts involved varying degrees of subjugation, tolerance, and integration, the Islamic world generally offered greater legal protection and cultural flourishing, whereas Christian Europe was often marked by systemic marginalisation, persecution, and violence. The differing theologies of Judaism within these host societies—Islamic recognition of monotheism versus Christian supersessionism—helped determine the contours of Jewish experience in each setting.

Jewish Life under Islamic Rule: Tolerance and Flourishing
With the rapid expansion of Islam in the 7th century CE, Jewish communities came under Umayyad and later Abbasid control, followed by a range of Islamic dynasties across the Middle East, North Africa, and the Iberian Peninsula. Jews were classified as dhimmis—non-Muslim monotheists granted protected status under Islamic law. Though required to pay a special tax (jizya) and abide by social restrictions, they were permitted to maintain their religion, govern internal affairs, and participate in economic and cultural life.

This relatively stable coexistence enabled a cultural renaissance, particularly during the Golden Age of Jewish life in Muslim Spain (al-Andalus), from the 9th to 12th centuries. Under the Umayyad and later the Almoravid and Almohad rulers (with variation), Jewish communities thrived intellectually, artistically, and economically. This era produced towering figures such as:

• Rabbi Moses ben Maimon (Maimonides), whose works in philosophy (Guide for the Perplexed), law (Mishneh Torah), and medicine had enduring influence in both Jewish and Islamic scholarship.
• Judah Halevi, a poet and philosopher whose writings reflect deep spiritual yearning and love for Zion.
• Samuel ibn Naghrillah, a Talmudic scholar, poet, and political leader who served as vizier in Granada.

In these multicultural settings, Arabic became a major language of Jewish thought, and Jewish scholars often engaged with Islamic philosophy, science, and theology, contributing to a shared intellectual heritage.

Jewish Life under Christian Rule: Marginalisation and Violence
In contrast, medieval Christian Europe—particularly after the 11th century—was far less hospitable. Theological hostility towards Judaism, grounded in doctrines of supersessionism (the belief that Christianity had replaced Judaism in God’s covenant), fuelled social suspicion and political exclusion. Jews were often confined to specific professions (e.g., moneylending, medicine), barred from land ownership, and subjected to special taxes.

Persecutions increased dramatically during periods of political instability and religious fervour, with Jews frequently scapegoated for natural disasters, economic crises, or theological nonconformity. Key episodes include:

• The Crusades: The First Crusade (1096) unleashed massacres of Jewish communities across the Rhineland (e.g., Mainz, Worms, Speyer), with crusaders viewing Jews as enemies of Christ. Later crusades continued to bring violence and expulsion.
• Blood libels: From the 12th century onward, European Jews were accused of ritually murdering Christian children, often leading to pogroms, executions, and forced conversions. These baseless accusations were repeated across Europe and contributed to deep-seated anti-Jewish myths.
• The Black Death (1348–1351): Amidst the pandemic, Jews were blamed for poisoning wells, leading to widespread massacres and expulsions.
• Expulsions: Between the 13th and 16th centuries, Jews were formally expelled from numerous kingdoms and cities, including England (1290), France (1306, 1394), Spain (1492), and Portugal (1497). These expulsions often involved confiscation of property, forced conversions, and years of wandering in search of new refuges.

Despite these challenges, Jewish life persisted and even flourished in certain European contexts, particularly in Ashkenazic centres of learning in Germany and later in Poland–Lithuania, which became a major hub of Jewish settlement and Talmudic study.

Comparative Dynamics and Adaptation
The contrast between Islamic and Christian dominions highlights the adaptive resilience of Jewish communities. Under Islamic rule, Jews frequently occupied positions of influence, participated in scientific and cultural exchange, and developed new schools of philosophy and law. Under Christian rule, survival often depended on forming tight-knit communities, strengthening legal and religious boundaries, and maintaining continuity through scholarship and ritual observance.

Jewish leaders—rabbis, poets, philosophers, merchants—acted as cultural mediators, often navigating perilous political landscapes while preserving communal autonomy. The emergence of Jewish legal codes, such as the Shulchan Aruch, and the institutionalisation of community councils (kehilla), helped preserve Jewish life across diverse and often hostile environments.

Conclusion
The experience of Jews under Christian and Islamic empires shaped the trajectory of post-Temple Judaism. While Islamic lands generally permitted cultural integration and intellectual flourishing—especially during the Golden Age in Spain—Christian Europe was characterised by marginalisation, theological hostility, and episodes of violence. Nevertheless, Jewish communities in both contexts demonstrated remarkable cultural endurance, legal ingenuity, and spiritual depth, preserving their identity and laying the foundations for the global Jewish diaspora that would evolve through the early modern and modern eras.