There are indications that the present location of the village must have been inhabited since prehistoric times. The first written mention about Sommersdorf was made in 10 Century (a recording of the Monastery St. Ludgeri in Helmstedt, located 8 km from the village). The village is mentioned in a record of goods written in 983. In later documents, the name of the village has changed, in the following sequence:
Sumirstorp 1191 (Kloster Marienborn)
Sommerstorp 1306, 1359, 1365, 1413, 1458,1481
During the Middle Ages, are few, but existing documents, inform about almost everything. There are names of people in the main documents on donations from farms and fields of monasteries and nobles. Of importance for the development of the village in the middle ages, was the struggle by Henry the lion of Sommerschenburg, Duke of Brunswick and Lüneburg and the Archbishop Wichmann of Magdeburg, beginning in 1181 and ending in 1208, when the fight between the German King Otto IV against King Philip of Swabia, came to an end with the death of the latter in 21 June 1208. From 1208-
In the war of the farmers in 1525, approximately 10 miles south, the peasants were completely looted. The population then moved north (Marienborn, which is approximately 6 km to the North).