Didrik Pining has been found by modern German genealogists to have been a native of Hildesheim in Germany, and this has according to a report been "suddenly and conclusively proved." It had been assumed that he was a Dane or Norwegian until the 1930s.
In Hanseatic records until 1468, he is mentioned as a privateer or captain in the service of Hamburg, charged with hunting down English merchant ships in the North Atlantic. From 1468 to 1478, he was in the service of Denmark (by 1470 as an "admiral") first under Christian I of Denmark (ruled 1448–1481), and later for his son, John of Denmark (ruled 1481–1513). Before his employment by the Danes, Pining and his partner Hans Pothorst had also been regarded by the Hanseatic League as "pirates who did much damage to the Hanse towns." During the later years of the reign of Christian I, Pining and Pothorst are said to have distinguished themselves "not less as capable seamen than as matchless freebooters."