"When King Gustaf III was preparing an attack on Denmark in 1783 he wrote to his chief aide-de-camp, Colonel Toll, that he was extremely busy and needed to write in French rather than in Swedish because it took so much less time. It is true that he was unusually good at French: even Vergennes, who did not like him at all, acknowledged his exceptional command of the French language. But he was not unique. The whole of northern Europe was dominated in the same way by the French language and French culture. Frederick II of Prussia, the Empress Catherine II of Russia, the Emperors Joseph II and Leopold II of Austria, the kings of Denmark and Poland – all of them spoke and wrote French fluently; and some of them, like Catherine II, wrote it in a fine, literary style. King Adolf Fredrik of Sweden and his queen both came from Germany as adults, but their son Gustaf never learned to understand German. French was the language in which he was educated, and Queen Louisa Ulrica insisted in his youth that he should write one letter in French to her every day. Indeed correspondence between members of the royal family was generally carried on in French at this time."