the dollar is named after the thaler. the thaler was a large silver coin first made in the year 1518. the thaler named after the joachimsthal (joachim's valley) mine in bohemia ("thal" means valley in german). the later spanish peso was the same size and was often called "spanish dollar" and the similar coin of the dutch republic was called “lion dollar”. in the 18th century it became a world currency. many national currencies were originally spanish dollars including the ones now called dollar or peso and the japanese yenand chinese renminbi.