Deventer (; Sallands: ) is a city and municipality in the Salland historical region of the province of Overijssel, Netherlands. In 2020, Deventer had a population of 100,913. The city is largely situated on the east bank of the river IJssel, but it also has a small part of its territory on the west bank. In 2005 the municipality of Bathmen (with a population of about 5,000 people) was merged with Deventer as part of a national effort to reduce bureaucracy in the country. Deventer is one of the oldest cities in the Netherlands. The place is mentioned in 9th-century sources from the Diocese of Utrecht. A charter from 877 AD mentions seven hooves in Daventre portu (the Deventer harbor). In 952 AD, Deventer is mentioned as a city in a gift certificate from King Otto I. After the place had acquired more and more rights and privileges over time, it received the municipal lands from Emperor Henry V in 1123. This is considered by historians to be the moment of Deventer obtaining the city rights by the inhabitants. The city has the oldest stone house, the oldest walking park and with the Athenaeum library also the oldest scientific library in the Netherlands. History Foundation and development in the Middle Ages Deventer was probably founded around 768 AD by the English missionary Lebuinus, who built a wooden church on the east bank of the river IJssel. In January 772 AD the sack and burning of this church by a Saxon expedition was the cause for the first punitive war waged by Charlemagne to the Saxons, in which, in retribution, the Irminsul (the Saxon sacred tree, probably near modern Paderborn) was destroyed. This was not the first human settlement at the location; between 1981 and 2006, remains of a late Roman Iron Age settlement (dated to c.300 AD) were excavated at Colmschate, 4 km east of the current city The village of Deventer, already important because of a trading road crossing the river IJssel, was looted and burnt down by the Vikings in 882. It was immediately rebuilt and fortified with an earthen wall (in the street Stenen Wal remains of this wall have been excavated and restored). Deventer received city rights in 956, after which fortifications were built or replaced by stone walls around the city for defense. Between 1000 and 1500, Deventer grew to be a flourishing trade city