This book examines the Lukan themes of unity and disunity against ancient Greco-Roman and Jewish social and political discourses on concord and discord to better understand the context in which Luke highlights the themes of unity and disunity. The themes of unity and disunity are particularly prominent in ancient discussions of the reigns of rulers, evaluations of laws/constitutions/forms of government, and descriptions of the contrasting effects of unity and disunity in the destruction and preservation of peoples and cities. These themes are grouped under the broad categories of kingship and law, and the preservation and destruction of cities. The book contends that, in the context of its literary setting, the theme of the unity of the church under one Lord in Acts contributes to Lukan Christological claims that Christ is the true king, and Lukan ecclesiological claims that the Christian community is the true people of God.