The arrival of the Spaniards to the Philippines attracted new waves of immigrants from China, and maritime trade flourished during the Spanish period. The Spanish recruited thousands of Chinese migrant workers called "sangleys" to build the colonial infrastructure in the islands. Many Chinese immigrants converted to Christianity, intermarried with the locals, and adopted Hispanized names and customs and became assimilated, although the children of unions between Filipinos and Chinese that became assimilated continued to be designated in official records as "mestizos de sangley". The Chinese mestizos were largely confined to the Binondo area until the 19th century. However, they eventually spread all over the islands, and became traders, landowners, and moneylenders.