This paper analyzes the intertwining of land taxation and merchant capital at a time when the Fatimid Caliphate was the regional hegemon of Southwest Asia and the Mediterranean. The Fatimids’ powerhouse was Egypt, among the most fertile and densely populated regions of the preindustrial world, and strategically positioned to monopolize transit trade between the Mediterranean and the Indian Ocean. The relevance of Fatimid Egypt is further enhanced by the availability of the Cairo Geniza. An extraordinary repository of more than 400,000 discarded leaves, the Geniza preserved hundreds of merchant letters, accounts, administrative documents, state decrees, and tax receipts, affording a quantity and quality of evidence unmatched until Ottoman era archives. Triangulating between Geniza documents, Arabic papyri from the Egyptian countryside, and fiscal manuals penned by Fatimid bureaucrats, this paper will chronicle the unfolding of a profound transformation in the political economy of Egypt, arguing that Fatimid taxation policies opened the way for the rise of new class of merchant capitalists who combined super-profits from the spice trade with massive investments in agricultural production. For nearly a thousand years before the advent of the Fatimids, Egypt’s agricultural surplus had been collected as tax to feed distant imperial capitals – Rome, Constantinople, Medina, Damascus. The fragmentation of the Abbasid Caliphate interrupted this millennial dependency. Eager to monetize Egypt’s exceptional fertility to finance their imperial ambitions, the Fatimids switched from taxation in kind to taxation in cash. Peasant households who previously surrendered a portion of their harvest now had to sell their produce to procure tax-money. The whole system would not have worked had Egyptian merchants not been ready to invest staggering amounts of money-capital in the purchase of this produce. Luckily for the Fatimids and unluckily for the peasants, Egyptian merchants were uniquely equipped to rise to the challenge. Their monopolistic position at the interface of the Indian Ocean and Mediterranean afforded them enormous arbitrage profits in the spice trade, and allowed for the accumulation of immense fortunes. Particularly wealthy and well-connected merchants thus started striking deals with the state to pay taxes on behalf of peasants, acquiring in return a state-backed claim to their produce. It is this entanglement of state and capital which I style the ‘fiscal-commercial complex.’ By documenting the symbiotic ascent of monetized taxation and merchant capital, this paper aims to revive the call for a reassessment of the longue durée history of capitalism out-side and “before European hegemony.”