What is a question about this article? If the question is unanswerable, say "unanswerable".

After the expulsion of the German population ethnic Russians, Belarusians, and Ukrainians were settled in the northern part. In the Soviet part of the region, a policy of eliminating all remnants of German history was pursued. All German place names were replaced by new Russian names. The exclave was a military zone, which was closed to foreigners; Soviet citizens could only enter with special permission. In 1967 the remnants of Königsberg Castle were demolished on the orders of Leonid Brezhnev to make way for a new "House of the Soviets".

In what year did Leonid Brezhnev come to power?
unanswerable