Despite Elizabeth's promise, there was still cruelty in her regime. Although she initially thought of allowing the young tsar and his mother to leave Russia, she imprisoned them later in a Shlisselburg Fortress, worried that they would stir up trouble for her in other parts of Europe. Fearing a coup on Ivan's favour, Elizabeth set about destroying all papers, coins or anything else depicting or mentioning Ivan. She had issued an order that if any attempt were made for the adult Ivan to escape, he was to be eliminated. Catherine the Great upheld the order, and when an attempt was made, he was killed and secretly buried within the fortress.