Analysis of information sources in references of the Wikipedia article "Morta of Lithuania" in English language version.
(...) Mindaugas' coronation was a consequence of the establishment of the Kingdom of Lithuania, not a cause. The Kingdom of Lithuania had been officially legalized (...) on July 17, 1251 by a bull of Pope Innocent IV. It was then that the Pope gave permission and an order to crown Mindaugas the King of Lithuania. This was the true international recognition of the Kingdom of Lithuania.