Why Is The Dollar Sign A Letter 'S'?

The letter 'S' appears nowhere in the word "dollar", yet an 'S' with a line through it ($) is unmistakably the dollar sign. But why an 'S'? Why isn't the dollar sign something like a 'D' (like the former South Vietnamese đồng, or the totally-not-a-joke-currency Dogecoin)?

There's a good story behind it, but here's a big hint: the dollar sign isn't a dollar sign.

It's a peso sign!

Bohemian Rhapsody
Though the dollar and peso symbols are inextricably linked, the origin of the word "dollar" is rooted  elsewhere. Its story begins in 1500s Bohemia, a central European kingdom spanning most of today's Czech Republic.

Central Europe had just become rich with silver. After centuries of sending its silver (and gold) abroad in trade for consumable luxuries like silk and spices (very little of which ever found its way back), new sources of silver ore were discovered in Saxony, German Tyrol and Bohemia. 

With far more silver than still-scarce gold, Tyrol began replacing its teeny-tiny gold coins with big heavy silver coins of equal value. The newly-minted guldengroschen coin, 32g of nearly-pure silver, was an instant hit.

Fast forward to 1519. The Kingdom of Bohemia's Joachimsthal region was finally producing enough silver to begin minting a heavy silver coin of its own. 

This new Bohemian joachimsthaler coin improved on the guldengroschen, adjusting the weight and purity slightly to make the coin evenly divisible into existing European weights and measures. 

It rapidly became the new European favorite, and soon most anyone with silver was minting their own version. The thaler suffix came to refer to any and all of these similar heavy silver coins . . . 

And over the next few decades the thaler coins came to have several transliterated variations on their names: the Slovenian taler, Dutch daalder, and in English, the word thaler became dollar.

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