Dassel is the endpoint of a private train line from Einbeck. "Carl Sasse, Dassel - Casala" is a well known furniture manufacturer, who in the 1950s delivered school, office and laboratory furnitures to all schools and universities in southern lower saxony.
Dassel dates back to the year 860, and received city rights in 1315. On March 1, 1974, Dassel was merged with several other small municipalities of the Ilme valley. The new city now covers the area of the historic county Dassel, which ceased to exist in 1310.