Jón Sigurðsson (yōn sĬ´khürŧħsōn), 1811–79, Icelandic statesman and historian. A student in Copenhagen from 1833, he developed an interest in Icelandic literature and history, on which he became the outstanding authority. He was active in many learned societies, which published his editions of the sagas and other literary works. As secretary (1840), later president (1851), of the Icelandic Literary Society, he directed the publication of monumental studies in Icelandic history and literature; he began the series Diplomatarium Islandicum in 1857. He served twice (1849–57, 1865–79) as president of the Althing, or parliament, but his journalistic activity was his great contribution to the Icelandic political revival. In 1841 he founded the periodical Ny felagsrit, the most influential Icelandic political journal, which endured until 1873. The constitution granted to Iceland in 1874 was largely the result of Sigurðsson's efforts, as was the grant of free trade (1854). During most of these years he lived in Copenhagen, the leader of a group of Icelandic writers, scholars, and diplomats.