Odense Odense River to the south and Naesbyhoved Lake (now dry) to the north. Nonnebakken, one of Denmark's former Viking ring fortresses, lay to the south of the river. Today, Odense's Møntergården Museum has many artefacts related to the early Viking history in the Odense area. The Vikings built numerous fortifications along the river banks to defend it against invaders coming in from the coast. The city celebrated its thousandth anniversary in 1988, commemorating the first mention of the town's name in a letter dated 18 March 988 from the German Emperor Otto III which granted rights to Odense and neighbouring
Odense early 20th century. The 1901 census recorded 40,138 people, growing to 47,224 in 1911, 61,969 in 1921 and 87,090 in 1935. During the Second World War, the population passed the 100,000 mark, reaching 103,107 in 1945. It continued to grow in the post war years, with 120,570 recorded in 1955 and 133,384 in 1965; the city reached a population of 139,490 people in 1970, a time when it was developing as a university city after Odense University was established in 1966. Residents began to move out of the centre into the suburban areas which were included in Odense Municipality after