Hauptbeschälerbuch Trakehnen N 870 (SBTrk. VI, S. 675, HBOpr. 1936 Nr. 3624); DE 399 9914721; 1185 POL (OST.HB.II 71,09 03624 30 BRD)
Foaled in 1930, Polarstern was used with very good effect on the black Trakehner herd based at the Gurdzen farm and contributed the bone and substance which was required at that period in the breed history, while still passing on breed type and quality. Sixteen stallions which were standing at Trakehnen just before its destruction were all evacuated in the autumn of 1944.