Ostruble (German: Ostrubel) is the name given to a currency denominated in kopeck and ruble, which was issued by Germany in 1916 for use in the eastern areas under German occupation (Ober Ost and the Government General of Warsaw). It was initially equal to the Russian ruble. The reason for the issue was a shortage of rubles. The banknotes were produced by the "Darlehnskasse" in Posen (now Poznań) on 17 April 1916.
From 4 April 1918, the Ostruble circulated alongside the Ostmark in the Ober Ost area, with 2 Ostmarks = 1 Ostruble. In the Government General of Warsaw the Ostruble was replaced by the Polish marka on 14 April 1917.
The denominations available were:
- 20 kopecks;
- 50 kopecks;
- 1 ruble;
- 3 rubles;
- 10 rubles;
- 25 rubles;
- 100 rubles.
The front sides of the banknotes carry a warning in German against forging banknotes. On the reverse sides is the same warning in Latvian, Lithuanian and Polish.
There were also 1 kopeck, 2 kopecks and 3 kopecks coins, made out of iron.
It was also still in use in a part of the Second Polish Republic during the first months of independence, until 29 April 1920.
- Gerhard Hahne, Die Inflation der Markwährungen und das postalische Geschehen im litauisch-polnischen Raum, Forschungsgemeinschaft Litauen im Bund Deutscher Philatelisten e.V., Uetze, (1996) (in German).
- N. Jakimovs and V. Marcilger, The Postal and Monetary History of Latvia 1918-1945, own book, 1991, pp. 14–13 - 14-15.