 Merging of these styles occurred during the period when the Holy Roman Empire and the Burgundy were part of the dominions under Charles I (king of Spain from 1516 to 1556), since composers from the North of Europe visited Spain, and native Spaniards traveled within the empire, which extended to the Netherlands, Germany and Italy.Music composed for the vihuela by Luis de Milán, Alonso Mudarra and Luis de Narváez was one of the main achievements of the period.The Aragonese Gaspar Sanz authored the first learning method for guitar.