Task: Explanation
Input (English): William II of Holland (February 1227 – 28 January 1256) was a Count of Holland and Zeeland (1234–56). He was elected as German anti-king in 1247 and remained king until his death. Question: John, was the Count of Auxonne and Chalon-sur-Saône in his own right, was a French nobleman, in contemporary documents, he was sometimes called "Count of Burgundy", in 1251, by which King? Answer: William II of Holland
Output (English): William II of Holland February 1227 – 28 January 1256 was a Count of Holland and Zeeland 1234–56.