In 1633, the brilliant Italian astronomer Galileo Galilei was tried and condemned by the Roman Inquisition in Rome, Italy, for defending heliocentrism—the scientific theory that the Earth revolves around the Sun. The Catholic Church ruled that heliocentrism contradicted traditional literal interpretations of Scripture, forcing Galileo to recant his findings and placing him under house arrest for the rest of his life. This historic trial became a defining symbol of the complex, often tense relationship between emerging modern scientific inquiry and established religious authority.

This intellectual crisis forced poets to re-examine their traditional understandings of a comfortable, Earth-centered cosmos. John Milton, who famously visited the aging Galileo under house arrest, incorporated this vast, disorienting new heliocentric astronomical perspective directly into the cosmic scale of 'Paradise Lost'.