Alfonso _el Sabio_ did not write in a vulgar dialect, but in the cultivated and polished language used by the aristocracy of Galicia. “The popular Gallegan dialect remained in the land of its birth, and kept the characteristic of a euphonic dialect,” says Valmar; but the language of learning ‘el Gallego erudito,’ so skilfully used by Alfonso and those innumerable Portuguese Spanish poets whose work is preserved in the Cancionero of the Vatican, acquired (without losing the essence of the primitive dialect) the character of a refined literary language. This language it was which became the mother of Portuguese.
The trouvadores of Aquitaine came in such numbers to Santiago, that it is no wonder they founded a centre of poetical unification, as Theophile Braga has called it. It was a school of national lyric poetry in the language which has been called Galaico-Portuguese. French influence was strongly reflected in it. It reached its highest point of resplendence in the reign of Alfonso X., and at that time even the lower classes understood and appreciated its poetry; so historians need be surprised no longer that the poet king chose to write in the language of Galicia.
Valmar has made a critical study of the versification of the _Cantigas_.[79] “In vain,” he says, “philologists have sought a connecting link between Latin prosody and the prosody of the Romance languages.” To write Hexameters in the language of Galicia would be impossible. The origin of the _Cantigas_ is undoubtedly the popular and religious poetry of Latin decadence, at the moment when there was added to it a rhythmic element. There were, in Roman days, two Latin versifications, rhythmic and metric, corresponding to the two idioms _sermo plebius_ and _sermo patricius_. The rhythmic versification used in popular poetry existed from the earliest days of Rome. It is mentioned by Livy, Cicero, Horace, and many other literary Romans. In the primitive hymns used by the Christian Church, the metric and rhythmic principles were curiously mixed. The earliest of these were composed by St. Ambrose and sung in Milan in 386. Léon Gautier has remarked that the poetry of France originated with the verses sung in the churches.