Alfred Tennyson, 1st Baron Tennyson FRS (/ˈtɛnɪsən/; 6 August 1809 – 6 October 1892) was an English poet. He was Poet Laureate of the United Kingdom during much of Queen Victoria's reign. In 1829 he was awarded the Chancellor's Gold Medal at Cambridge for one of his first pieces, "Timbuktu". He published his first solo collection of poems, Poems, Chiefly Lyrical, in 1830. "Claribel" and "Mariana", which remain some of Tennyson's most celebrated poems, were included in this volume. Although described by some critics as overly sentimental, his poems ultimately proved popular and brought Tennyson to the attention of well-known writers of the day, including Samuel Taylor Coleridge. Tennyson's early poetry, with its medievalism and powerful visual imagery, was a major influence on the Pre-Raphaelite Brotherhood.

Tennyson also focused on short lyrics, such as "Break, Break, Break", "The Charge of the Light Brigade", "Tears, Idle Tears", and "Crossing the Bar". Much of his verse was based on classical mythological themes, such as "Ulysses" and "The Lotos-Eaters". "In Memoriam A.H.H." was written to commemorate his friend Arthur Hallam, a fellow poet and student at Trinity College, Cambridge, after he died of a stroke at the age of 22. Tennyson also wrote notable blank verse, including Idylls of the King, "Ulysses", and "Tithonus". During his career, Tennyson attempted drama, but his plays enjoyed little success.

A number of phrases from Tennyson's work have become commonplace in the English language, including "Nature, red in tooth and claw" ("In Memoriam A.H.H."), "'Tis better to have loved and lost / Than never to have loved at all", "Theirs not to reason why, / Theirs but to do and die", "My strength is as the strength of ten, / Because my heart is pure", "To strive, to seek, to find, and not to yield", "Knowledge comes, but Wisdom lingers", and "The old order changeth, yielding place to new". He is the ninth most frequently quoted writer in The Oxford Dictionary of Quotations.

Alfred Tennyson was born on 6 August 1809 in Somersby, Lincolnshire, England. He was born into a successful middle-class family of minor landowning status distantly descended from John Savage, 2nd Earl Rivers, and Francis Leke, 1st Earl of Scarsdale.

His father, George Clayton Tennyson, was an Anglican clergyman who served as rector of Somersby (1807–1831), also rector of Benniworth (1802–1831) and Bag Enderby, and vicar of Grimsby (1815). He raised a large family and "was a man of superior abilities and varied attainments, who tried his hand with fair success in architecture, painting, music, and poetry. He was comfortably well off for a country clergyman, and his shrewd money management enabled the family to spend summers at Mablethorpe and Skegness on the eastern coast of England". George Clayton Tennyson was the elder son of the attorney and member of Parliament George Tennyson, JP, DL, of Bayons Manor and Usselby Hall, who had also inherited the estates of his mother's family, the Claytons, and married Mary, daughter and heiress of John Turner, of Caistor, Lincolnshire. George Clayton Tennyson was however pushed into a career in the church and passed over as heir in favour of his younger brother Charles. Their mother, Elizabeth, was the daughter of Stephen Fytche,^{[citation needed]} vicar of St James' Church, Louth (1764), and rector of Withcall (1780), a small village between Horncastle and Louth. Tennyson's father "carefully attended to the education and training of his children".

Tennyson, recalling the poetic influences of his youth, said, "as a boy I was an enormous admirer of Byron." Tennyson and two of his elder brothers were writing poetry in their teens, and a collection of poems by all three was published locally when Alfred was 17. One of those brothers, Charles Tennyson Turner, later married Louisa Sellwood, the younger sister of Alfred's future wife; the other was Frederick Tennyson. Another of Tennyson's brothers, Edward Tennyson, was institutionalised at a private asylum.

The psychologist William James, in his book The Varieties of Religious Experience, quoted Tennyson concerning a type of experience with which Tennyson was familiar:

A kind of waking trance I have frequently had, quite up from boyhood, when I have been all alone. This has often come upon me through repeating my own name. All at once, as it were out of the intensity of the consciousness of individuality, individuality itself seemed to dissolve and fade away into boundless being, and this was not a confused state but the clearest, the surest of the sure, utterly beyond words…