In the 18th century, many Spanish civilians (mainly of Basque origin) entered the country, in particular attracted by trade liberalization at the time enacted by the Spanish Crown. In the late 18th century, Basque descendants were estimated to comprise 27% of the total population. Most of the Basque immigrants initially partook in small businesses, though others attained higher levels of prosperity. Of those, many mixed with the Criollo aristocracy of Castilian origin, who owned much of the land. This resulted in the "Castilian-Basque" aristocracy, which later came to form the basis of the Chilean ruling class; other Basques also integrated with mestizo population of Castilian origin, that resulted in modern Chilean middle classes. The number of descendants from Basques in Chile are estimated at 10% of the population (1.7 million).