Dylan Thomas’s “Poem on His Birthday,” written in 1949 and published two years later, deeply explores the big questions about life, death, and spirituality. Set against the backdrop of the natural world, the poem uses vivid images to explore themes of the cyclical nature of existence, the connection between all living things, and the mysterious aspects of life and death. The rough and beautiful landscapes of Thomas’s home in Wales play a large role, adding a symbolic touch to his thoughts about mortality.

In the opening stanza, Thomas sets the scene, describing the sun over a river and a tidal shoreline. Writing from a boathouse that sits above the water “on stilts high,” Thomas contemplates entering midlife. He notes that this “sandgrain” day is just another moment gone by as if through an hourglass.

This stanza introduces an ambiguous tone as the poet reflects on his thirty-fifth birthday while emphasizing the cycle of life and death. He is celebrating and mourning this milestone all at once. At this moment, Thomas feels like “driftwood” floating in on the tide. The stanza establishes the thematic foundation of nature’s beauty, the passing of time, and the intertwining of the speaker’s journey with the elements of the natural world.

In the second stanza, Thomas draws comparisons between his existence and the creatures around him:

Under and round him go
Flounders, gulls, on their cold, dying trails,
Doing what they are told . . .

These creatures, like “the rhymer in the long tongued room / Who tolls his birthday bell,” are merely doing what their instincts tell them as they move through life toward an inevitable death. While this stanza takes on a bleak tone, it ends with a symbol of hope as “steeple stemmed” herons rise up to bestow blessings.

The third stanza continues the exploration of mortality with an allusion to the changing seasons and the predatory aspects of wild creatures. Finches are caught by hawks, and fish swim through the wrecks of sunken ships to be eaten by otters. The herons from the previous stanza are still present, but now they “walk in their shroud,” as if to a funeral. The natural world has a sense of movement and transformation, and the speaker acknowledges the interconnectedness of life and death.

In the fourth stanza, Thomas further explores the relationship between life and death and the never-ending cycle of nature’s processes. Here, the poet turns his attention to the river, where minnows flow like a robe, swirling in prayer-like formations. The poet contemplates the vastness of the sea, where “dolphins dive” and “rippled seals streak down” after their prey. There will come a time when even these hunters of the sea must themselves die, meeting their end “in the sleek mouth” of other predators.

The tone changes in the fifth stanza to one of quiet contemplation as the poet imagines a wave stopping mid-movement to form a cavern. In the silence of this unmoving water, “Thirty five bells sing,” one ring for each year of Thomas’s life. These bells signify a new start where he can leave behind the unwanted remnants of his past as if they were sunken ships on the seafloor, sent to their doom as though “Steered by the falling stars.”

Freed from past and future anxieties, Thomas wonders where the rest of his life might take him in stanza six. He envisions himself going freely into the unknown, basking in the light of the divine. The poet finds it hard to imagine that heaven could even exist with its promised salvation. He contemplates that heaven may ultimately be...