Kėdainiai () is one of the oldest cities in Lithuania. It is located north of Kaunas on the banks of the Nevėžis River. First mentioned in the 1372 Livonian Chronicle of Hermann de Wartberge, its population is 23,667. Its old town dates to the 17th century. The city is the administrative centre of the Kėdainiai District Municipality. The geographical centre of the Lithuanian Republic is in the nearby village of Ruoščiai, located in the eldership of Dotnuva. Names The city has been known by other names: Kiejdany in Polish, Keidan (קיידאן) in Yiddish, and Kedahnen in German. Kėdainiai other alternate forms include Kidan, Kaidan, Keidany, Keydan, Kiedamjzeÿ ("j" /e/), Kuidany, and Kidainiai. History The area was the site of several battles during "The Deluge", the 17th century war between the Polish–Lithuanian Commonwealth and Sweden. In 1655 a short-lived treaty with Sweden, the Union of Kėdainiai, was signed by two members of Radziwiłł family in their Kėdainiai castle. While little remains of the Radziwiłł castle, the crypt of the Calvinist church (1631) houses the family mausoleum, including the tombs of Krzysztof Radziwiłł and his son Janusz. Scottish Protestants arrived in the late 16th and 17th centuries, encouraged by the conversion of Anna Radziwill; the community exerted considerable influence in the city and persisted until the mid-19th century. The grouping of the buildings around the town square still include the imposing homes of merchants known as the "Scottish Houses". These include; the George Anderson House, the John Arnot House, the George Bennet House, the James Gray House, the Steel Property, and the surviving basement of the Alexander Gordon house. A local custom called on all visitors to bring a stone to be used in the town's construction. World War II During Operation Barbarossa, Kėdainiai was occupied by the German Army in the summer of 1941. On August 28, 1941, the entire Jewish community of Kėdainiai, a community which had inhabited the area for 500 years, were killed under the direction of German Special Police Battalions, with the aid of the local Lithuanian population. The Jewish population prior to the Holocaust was 3000. Soviet period During the Cold War it was home to Kėdainiai air base, a major Soviet military airlift facility. For many years, Kėdainiai was known for its chemical and food processing industries. The Kėdainiai chemical plant, Lifosa began operations in January 1963. Publicized as a milestone in the industrialization of