Speaker/Coleridge
In the case of this poem, it is reasonable to assume that the poem's unnamed speaker is a version of Samuel Taylor Coleridge himself: the poem incorporates elements from the poet's life and is addressed to his friend Charles Lamb. At the start of the poem, the speaker loves both his friends and nature, but feels isolated from both. His friends have left him to hike through the country, forcing him to sit by himself under a tree, deprived of both natural beauty and company. However, as he imagines his friends taking joy in nature, he becomes increasingly elated, feeling closer to both the friends and the natural world as he pictures them. Eventually, he has an epiphany, realizing that connection to other people and the natural world is available at all times to those who are open to and appreciative of it.
Charles
Charles is one of the friends who the speaker laments he cannot join on the walk. The speaker repeatedly refers to him as "gentle-hearted Charles," and describes him as a quiet but deep individual with a keen appreciation for the natural world. The speaker clearly feels great love and tenderness for his friend, as well as pity. Charles, he explains, lives in the city and is isolated from nature, making him sad—though he avoids complaining about it. Moreover, his life has been difficult lately, and the chance to walk through the country offers him much-needed relief.
As with the speaker and Coleridge himself, the line between the Charles of the poem and Coleridge's real-life friend Charles Lamb is nearly nonexistent. Lamb was an English writer and close friend of Coleridge. The poem is dedicated to him, encouraging readers to assume that he is the Charles addressed in the poem itself. Furthermore, the "strange calamity" identified in the poem likely refers to the tragedy in which Lamb's sister, during a period of acute mental illness, killed his mother. Additional knowledge of Lamb's personal life is not needed to appreciate the poem, but adds an additional layer of depth to the speaker's sympathy for his friend.
