Thaler
The thaler was a silver coin used throughout Europe for almost four hundred years. Its name lives on in the many currencies called dollar and until recently, the Slovenian tolar. Further, the name of the Romanian and Moldovan currencies (Romanian and Moldovan Leu) comes from the Thaler via one of the Dutch daalders, the leeuwendaalder ("lion thaler").
Etymologically, "thaler" is an abbreviation of "Joachimsthaler", a coin type from the city of Joachimsthal (Jáchymov) in Bohemia, where some of the first such coins were minted in 1518. Thal is German for "valley" - a "thaler" is a person or a thing "from the valley". In the 1902 spelling reform, the German spelling was changed from Thal and Thaler to Tal and Taler, which however did not affect the spelling of "thaler" in English. The Czech spelling was tolar; many varieties of the term are used in different languages.
Origin
The roots and development of the thaler-sized silver coin date back to the mid-15th century. As the 15th century drew to a close the state of much of Europe's coinage was quite poor because of repeated debasement induced by the costs of continual warfare, and by the incessant centuries-long loss of silver and gold in indirect one-sided trades importing spices, porcelain, silk and other fine cloths and exotic goods from India, Indonesia and the Far East. This continual debasement had reached a point that silver content in Groschen-type coins had dropped, in some cases, to less than five percent, making the coins of much less individual value than they had in the beginning.