Northeim is a town in Lower Saxony, Germany, seat of the district of Northeim, with a population of 30,118 as of 31 December 2023. It lieā¦Northeim is a town in Lower Saxony, Germany, seat of the district of Northeim, with a population of 30,118 as of 31 December 2023. It lies on the German Half-Timbered House Road. Northeim is first mentioned in 800 in a document recording a property transfer by a Frankish nobleman to the Abbey of Fulda. In the 10th century the surrounding region became a county, administered by the Counts of Northeim. The first of them, Siegfried is mentioned in 982. From 1061 to 1070 Count Otto II held the stem duchy of Bavaria as an Imperial fief, but lost it again because of his involvement in the Saxon plot against King Henry IV.