The first recorded usage of the term is attributed to Boleslaus George II of Halych. In a 1335 letter to Dietrich von Altenburg, the Grand Master of the Teutonic Knights, he styled himself «dux totius Rusiæ Minoris». The name was used by Patriarch Callistus I of Constantinople in 1361 when he created two metropolitan sees: Great Rus' in Vladimir and Kyiv and Little Rus' with its centers in Galich ("Halych") and Novgorodok ("Navahrudak"). King Casimir III of Poland was called "the king of Lechia and Little Rus'." According to Mykhaylo Hrushevsky, Little Rus' was the Halych-Volhynian Principality, after the downfall of which the name ceased to be used.