LONDON — The British Library has bought a valuable archive from the family of Samuel Taylor Coleridge that portrays the clan’s affectionate, if slightly bemused, view of its “presiding genius.”

In the nearly two centuries since Coleridge’s death, the papers have been kept by family members in Ottery St. Mary in Devon, England, where the creator of “Kubla Khan” and “The Rime of the Ancient Mariner” was born.

Highlights include a previously unknown manuscript of two of Coleridge’s poems, written in his own hand, and many reminiscences of the poet in the letters and diaries of other family members. Also in the archive are letters from eminent Victorians who were friends of the Coleridges, including Prime Minister William Ewart Gladstone, the leading cleric Cardinal John Newman, and architect Augustus Pugin.

“This is an archive of the whole Victorian era,” the library’s head of modern historical manuscripts, Frances Harris, said. The bulging archive, she said, “provides a family perspective on the family’s presiding genius. There is a powerful sense of affection and fascination” for the poet, who in his later years famously became “somewhat erratic” as his addiction to opium deepened and his health deteriorated. The library secured the archive after the family decided to sell Chantry House, bought by Coleridge’s brother, James, in 1796, and its contents.

Ms. Harris said more than 350 bound manuscripts and 29 cardboard boxes of correspondence made up the archive and may take a library staffer up to a year to catalog. The library has not announced how much it paid, but Ms. Harris called it “a significant six-figure sum.”