Task: Question Generation
Input (English): Catalan evolved from Vulgar Latin around the eastern Pyrenees in the 9th century. During the Low Middle Ages it saw a golden age as the literary and dominant language of the Crown of Aragon, and was widely used all over the Mediterranean. The union of Aragon with the other territories of Spain in 1479 marked the start of the decline of the language. In 1659 Spain ceded Northern Catalonia to France, and Catalan was banned in both states in the early 18th century. 19th-century Spain saw a Catalan literary revival, which culminated in the 1913 orthographic standardization, and the officialization of the language during the Second Spanish Republic (1931–39). However, the Francoist dictatorship (1939–75) banned the language again.
Output (English): What year started the decline of Catalan as a main language?