Publius Vergilius Maro (70 BCE-19 BCE), later called Virgilius, and known in English as Virgil or Vergil, was a classical Roman poet. He was the author of epics in three modes: the Bucolics or Eclogues (37 BC), The Georgics (29 BC) and the substantially completed The Aeneid (19 BC), the last being an epic poem in the heroic mode, which comprised twelve books and became the Roman Empire's national epic. Biographical reconstruction supposes that Virgil was part of the circle of Maecenas, Octavian's capable agent d'affaires who sought to counter sympathy for Mark Antony among the leading families by rallying Roman literary figures to Octavian's side. It also appears that Virgil gained many connections with other leading literary figures of the time, including Horace and Varius Rufus. As the Roman Empire collapsed, literate men acknowledged that the Christianized Virgil was a master poet. The Aeneid remained the central Latin literary text of the Middle Ages. It also held religious importance as it describes the founding of the Holy City. Surviving medieval collections of manuscripts containing Virgil's works include the Vergilius Augusteus, the Vergilius Vaticanus and the Vergilius Romanus.