Reichsthaler
The Reichsthaler was a standard Thaler of the Holy Roman Empire, established in 1566 by the Leipzig convention. It was also the name of a unit of account in northern Germany and of a silver coin issued by Prussia.
Reichsthaler coin
The Leipzig convention set the Reichsthaler as a coin containing 1/9 of a Cologne mark of silver. The various German states within the Empire issued Reichsthaler together with smaller coins according to whatever system of subdivisions they chose. In 1754, the Conventionsthaler (containing 1/10 of a mark of silver) replaced the Reichsthaler as the standard.
Reichsthaler unit of account
At the same time as the Reichsthaler was being issued as a coin, it was also being used in much of Northern Germany as a unit of account, with the unit of account being worth ¾ of the value of a Reichsthaler coin. As a unit of account, the Reichsthaler was therefore equivalent to 1⁄12 of a Cologne mark of silver. After 1754, this unit (now ¾ of a Convenstionsthaler, 3⁄40 of a mark of silver) continued to be used, although it was more commonly referred to as simply a Thaler.
In most of the states using the Reichsthaler as a unit of account, it was subdivided into 288 Pfennig, with intermediate denominations such as the Groschen or Gutegroschen, worth 12 Pfennig (1/24 of a Reichsthaler), and the Mariengroschen, worth 8 Pfennig (1/36 of a Reichsthaler).
Prussian Reichsthaler
In 1750, Prussia adopted a Reichsthaler (also often called the thaler) containing 1/14 of a Cologne mark of silver. This standard was referred to as the "Graumannscher Fuß" after Philipp Graumann, its originator. For more information, see Prussian Thaler.
During the early 19th century, the smaller Prussian standard for the Reichsthaler replaced the larger standard in most of northern Germany. See Hannovarian Thaler, Hesse-Kassel (or Hesse-Cassel) Thaler, Mecklenburg Thaler and Saxon Thaler.
The Prussian standard also became part of the currency used in southern Germany following the currency union of 1837. The thaler was worth 1¾ Gulden.
These Thaler were replaced by the Vereinsthaler, of almost the same weight, in 1857.