1915 AD., Germany, 2nd Empire, Saxe-Weimar-Eisenach, Wilhelm Ernst, 100th anniversary of the Grand Duchy of Saxe-Weimar-Eisenach commemorative, Berlin mint, KM 222.

Germany, 2nd Empire, Saxe-Weimar-Eisenach, Wilhelm Ernst (1901-1918), 100th anniversary of the Grand Duchy of Saxe-Weimar-Eisenach commemorative, Berlin mint, 1915 AD.,
3 Mark (Taler) (ø 33 mm / 15,48 g), 0.900 silver, 16,67 g. theor. mint weight, mintage 50.000 , axes medal alignment ↑↑ (0°), (later filed) plain edge with insription "GOTT ~+~ MIT ~+~ U[N]S ~+~ ",
Obv.: WILHELM ERNST MCMXV - CARL AUGUST MDCCCXV · / A , Grand Duke Wilhelm Ernst and Grand Duke Carl August, their conjoined busts in military uniforms facing right, mint mark "A" at base of Wilhelm Ernst´s bust (the left one), dates 1915 and 1815 as Roman numerals in legend.
Rev.: DEUTSCHES REICH * 1915 / DREI MARK , crowned German imperial eagle, value below.
KM 222 ; Jaeger 163 ; Dav. 491 .
(damages at top and edge, probably by usage as jewelry with a hanger clip at top and circular setting)

Year / Mint Mark / Mintage
1915 / A / 50.000
1915 / A / ? (proof)

The Duchy of Saxe-Weimar-Eisenach (German: Herzogtum Sachsen-Weimar-Eisenach) was created in 1809 by the merger of the Ernestine duchies of Saxe-Weimar and Saxe-Eisenach. It was raised to a Grand duchy in 1815 by resolution of the Vienna Congress. In 1903, it officially changed its name to the Grand Duchy of Saxony (German: Großherzogtum Sachsen), but this name was rarely used. The Grand Duchy came to an end in the German Revolution of 1918–19 with the other monarchies of the German Empire. It was succeeded by the Free State of Saxe-Weimar-Eisenach, which was merged into the new state of Thuringia two years later.
more on https://en.wikipedia.org/wiki/Grand_Duchy_of_Saxe-Weimar-Eisenach