"Birthday Letters" is a collection of poems written by the British poet Ted Hughes in 1998. The book is a deeply personal reflection on his relationship with his late wife, Sylvia Plath, and explores themes of love, loss, and memory. Each poem serves as a letter, capturing Hughes's emotions and thoughts on significant moments in their lives. The collection is notable for its raw honesty and emotional depth, showcasing Hughes's unique poetic style. It provides insight into the complexities of their marriage and the impact of Plath's tragic death on Hughes's life and work.