The sister of Alfred Lord Tennyson who is engaged to Arthur Henry Hallam?

Alfred Lord Tennyson's sister who was engaged to Arthur Henry Hallam is Emily Tennyson. Their engagement was a significant relationship in Tennyson's life, inspiring some of his most famous poetry, particularly after Hallam's untimely death in 1833. Tennyson's grief over Hallam's passing deeply influenced his work, leading to the creation of the elegy "In Memoriam A.H.H."