The success of Islamic imperialism in the period from the conquests to the Ayyubid dynasty has traditionally been explained as purely the result of military might. This book, however, adopts a bottom-up approach which puts social relationships and local power dynamics at the centre of the Islamic empire's cohesion. Its chapters draw on sources in diverse languages: not just Arabic, but also Greek, Coptic, Syriac, Hebrew, and Bactrian, showing how different linguistic communities intersected and contributed to a connected yet diverse empire. They highlight how not just literary and historical texts, but also physical documents and archaeological evidence should be incorporated into writing histories of the late antique and early medieval Middle East. Social institutions and relationships explored include oaths; petitions, decrees, and begging letters; and financial frameworks such as debt and taxation. This title is also available as Open Access on Cambridge Core.