On May 8, 2025, Cardinal Robert Prevost became the first pope from the United States, choosing the papal name Leo XIV. As the fourteenth bearer of a name which translates from Latin to 'lion', his choice foregrounds long-standing values of authority, vigilance and spiritual courage in Catholic history. The Lion Returns to Rome: Pope Leo XIV, the Leonine Papacy and the Augustinian Tradition by Ambrose Mong begins by tracing the symbolic legacy of leonine imagery in the Bible, showing what this complex motif reveals about majesty and paradoxes in the Scriptures.

The Lion Returns to Rome then intimately ties Pope Leo XIV to Augustine's spiritual pilgrimage, from restlessness and searching towards deep peace with God. Mong explores the far-reaching influence of St. Augustine on the papacies of Leo I and Leo XIII and projects how Augustinian thought could shape the emerging priorities of Leo XIV. Through this exploration, the book argues that understanding Augustine's enduring presence in Catholic theology is key to discerning where the Church is headed under new leadership.