Byzantium and the Arabs in the Sixth Century, Volume 1, Part 1: Political and Military History is devoted to the main Arabian tribes that were federates of the Byzantine Roman Empire. In the early sixth century, Constantinople shifted its Arab alliance from the Saliids to the Kindites and especially the Ghassanids, who came to dominate Arab-Byzantine relations through the reign of Heraclius. Arranged chronologically, this study, the first in-depth account of the Ghassanids since the nineteenth century, draws widely from original sources in Greek, Syriac, and Arabic. Irfan Shahîd traces in detail the vicissitudes of the relationship between the Romans and the Ghassanids, and argues for the Ghassanid's extensive role in the defense of the Byzantine Empire in the east.