Middle Low German is a development step of the Low German language ("Niederdeutsch"). It was in use in the northern part of Germany. It developed from Old Saxon, in the Middle Ages. The first records date from the 13th century. It was one of the languages the Hanseatic League used. It also influenced the Nordic languages, such as Swedish, which took loanwords from it. At that time, it was also used for treaties and diplomacy. One of the surviving testimonies is the Sachsenspiegel.