The coins of the German States from this period are hard to understand. In the period 1821-1857, a large number of coinage treaties coalesced the situation around two coins:
- The Prussian Thaler of 30 groschen, each worth 12 pfennig, so 360 pfennig in a Thaler
- The Austrian Gulden of 20 Silbergroschen of 5 kreuzer
Within the Prussian Thaler area, there were several different systems, e.g. Mecklenburg (1 Thaler = 48 Schilling of 12 Pfenning), Oldenburg (1 Thaler = 30 Groschen of 12 Schwaren) ans Sachsen (1 Thaler = 30 Neugroschen of 10 Pfennig). Hannover was hemmed in between two parts of Prussia. It tried to remain independent by not acceding to any monetary convention and applying the Prussian system voluntarily from 1834. In 1854, Hannover changed over to the Saxonian system. Therefore, your coin is among the last pfennigs of 1/360 Thaler. From 1854 to 1866, when Hannover was added to Prussia, the pfennig was 1/300th Thaler.
Peter