The Dutch had ample time to leave their mark on Ceylon, as they held it from the middle of the seventeenth century, when they wrested it from the Portuguese, until the end of the eighteenth, when it was handed over to Great Britain at the time when Holland was subject to France. The Dutch traders were attracted to Colombo and the southwest coast by the cinnamon which grew there; the bark of the cinnamon was the most valuable product of Ceylon and almost the only export, apart from elephants, until well into the nineteenth century. The cinnamon trade was a strict government monopoly, enforced by harsh penal laws, and the monopoly remained, even under English rule, until 1832. One other interesting trace of Dutch rule survives in the many miles of palm groves, planted by forced native labour, which we have already noticed along the coast from Colombo to Galle. For a century and a half before the Dutch occupation the island was under the power of Portugal. The wars of the Dutch were undertaken to advance their trade; but the Portuguese fought for the idea of Empire, and one of their chief aims was the conversion of the conquered races to Christianity. The effect of Portuguese rule still survives in the coast districts where Portuguese names are common, in the mixed race and the local corrupt Portuguese dialect, and above all in the thousands of natives professing the Roman Catholic religion. The word Don, formerly a Portuguese title, is still in use among the natives as a personal name, and many even of the pure Sinhalese have adopted high-sounding Portuguese names.