'The Political Correspondence of Frederick the Great' Volume 48 of the highly reputed collection 'Politische Correspondenz Friedrichs des Großen' (The Political Correspondence of Frederick the Great), published since 1879 with interruptions, is based mainly on the sources of the 'Geheimes Staatsarchiv PK' at Berlin. It contains the diplomatic correspondence of the Prussian monarch with his ministers and diplomats at the European and some German courts. It covers the first half of the year 1783. The dominating issue for him (Frederick) were the declining relations with the ally Russia (since 1764) ever since the approach of Emperor Joseph from Austria to Empress Catherine II who was about to annex the Krim-Peninsular in 1783.