During whose reign was Virgil considered the most famous poet?

Virgil is most renowned for his epic poem "The Aeneid," which was written during the reign of Augustus Caesar. Augustus, who was the first Roman emperor, established a period of relative peace and stability known as the Pax Romana, which created an environment that encouraged arts and literature to flourish. Virgil's works were not only a reflection of this time but also served to promote Augustus's ideals and political agenda, especially the idea of Rome’s greatness and destiny.

Virgil became the most celebrated poet of this era because he embodied the cultural and ideological values that Augustus sought to promote. His writings reflect a blend of personal expression and social, political themes that aligned with Augustus's vision of Rome. Therefore, it is during Augustus Caesar's reign that Virgil reached the pinnacle of his fame and influence in literature.