Climate as Catalyst

This article examines a passage found in Arabic sources of the Abbasid period that explicitly links severe climatic events and political unrest—specifically, the rebellion in Mosul during the spring of 260/873 against a newly appointed governor’s deputy. The event is recorded by al-Azdī (d. 334/945–6), Ibn al-Athīr (d. 630/1233), and al-Nuwayrī (d. 733/1333), with the first two authors being native to Mosul, and their accounts coincide with other sources that reported a poor agricultural year in the region. According to the sources, the episode is notable for its mention of late and intense cold, with effects hinting at a frost, and seems to align with broader climatic anomalies recorded across Eurasia in the same period. The Mosul rebellion occurred against a background of fiscal discontent, exacerbated by a calendar system that advanced the tax year ahead of the harvest season, and growing tensions between the Jazīra region and the Abbasid capital. These intersecting environmental and social pressures help situate the Mosul revolt within broader patterns of instability in the empire. It would be from Mosul itself, ultimately, that the calendar would be reformed to correct this state of affairs by connecting it to a well-established understanding of seasonality in relation to agriculture. Keywords: Climate anomalies, Mosul revolt, Abbasid period, social pressures, calendar reform