In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

What happened on a celebrated birthday?, Context: On December 25, 1991, following the collapse of the Soviet Union, the republic was renamed the Russian Federation, which it remains to this day. This name and "Russia" were specified as the official state names in the April 21, 1992 amendment to the existing constitution and were retained as such in the 1993 Constitution of Russia.
existing constitution