I wonder whether we do really need the "Prussian supercentenarians" category.
Currently there are four supercentenarians included: http://gerontology.wikia.com/wiki/Category:Prussian_supercentenarians
I'd be cautious ro avoid overcategorization or mistakes here. Kingdom of Prussia existed between 1701-1918. Until 1934 we could speak of Free State of Prussia as part of the Weimar Republic. In 1947 Prussia was dissoved de jure. Today, the territory of former Prussia is part of Germany, Poland, Lithuania and Russia (Kaliningrad Oblast). In the period which interests us the most; namely, before 1907, Kingdom of Prussia existed not as an independent state, yet part of the German Empire - since its proclamation in 1871.
Therefore, I propose the category "Prussia births" or "Kingdom of Prussia births" for supercentenarians born before 1871 - in the independent state of Prussia, before it was included in the unified German state.