The English poet John Keats belonged to the Romantic period of poetry where poets wrote much about Nature and peppered their nature writing also with questions about man's place in it and within time. Poets such as Wordsworth wove ideas about duty and death into his romantic poems, and Keats (for example in "Ode on a Grecian Urn") examined ideas of time and man's existence in it. Nature was not only praised however, in this Romantic poetry. It's power, awesomeness and ability to hurt and destroy was also acknowledged and treated with respect. Previously, much of the grandeur of the world was put down to God's omnipotence but the mood was shifting to an appreciation of Nature's power for its own sake. Keats appealed to Nature to take him and comfort him in "Ode to a Nightingale."
Keats is considered a Romantic. The reason for this would be due to his embrace of items that are seen as Romantic ideals. For example, in much of Keats' work there is a reverence for nature and the natural setting. This is something that can be found in the works of the Romantic thinkers. In his odes on nightingales and autumn, this theme is highly present. Another reason why Keats is considered to be a Romantic would be for his lauding of the individual and subjective. Keats is driven by his belief that within the realm of individual experience and emotions, objective truth can be revealed and understood. Finally, the subjective experience allows Keats to advocate a form of "negative capability," which extols the virtue of the unknown and the elements of consciousness which cannot be explained through rationality and science. This embrace of that which is uncertain is another Romantic sensibility.
John Keats is a Romantic poet. That does not mean that his poems are about love and romance. Rather, romanticism was a reaction against the growing industrialization and a harking back to nature. As the enotes article on Romanticism states, these writers emphasized "the importance of the individual’s experience in the world and his or her interpretation of that experience, rather than interpretations handed down by the church or tradition."
The Romantic Period of English and American literature spans the years 1789 to 1832. Other Romantic poets include William Wordsworth, Samuel Taylor Coleridge, and Percy Shelley.