The old capital of Picardy, on the Somme, with a cathedral begun in 1220, described as the "Parthenon of Gothic architecture," and by Ruskin as "Gothic, clear of Roman tradition and of Arabian taint, Gothic pure, authoritative, unsurpassable, and unaccusable"; possesses other buildings of interest; was the birthplace of Peter the Hermit, and is celebrated for a treaty of peace between France and England concluded in 1802.