Complex sentence: During the time when the Stalinist leadership of Hungary would not permit his death to be commemorated, or permit access to his burial place, a cenotaph in his honour was erected in Père Lachaise Cemetery in Paris.
Split into simpler sentences: During the time when the Stalinist leadership of Hungary would not permit his death to be commemorated, or permit access to his burial place. A cenotaph in his honour was erected in Père Lachaise Cemetery in Paris.