A LETTER by one of Europe’s greatest rulers found in Oxford’s Bodleian Library offers a friend tips on treating venereal disease.

Previously unknown letters by Frederick the Great of Prussia were discovered by Prof Katrin Kohl, of Oxford University’s Faculty of Medieval and Modern Languages.

In one letter, written in French in 1732, the 20-year-old soldier Frederick writes to advise a fellow officer on where to go to treat his VD.

Inviting his friend to confide his secret to him, he writes: “I’ll make sure you have all the necessary medicine from Dr Miraux of Potsdam. (...) I’m going to Potsdam on Tuesday, and to Berlin on Wednesday. If you have some order to give to the Whores of Berlin, you have only to let me know.”

Frederick II of Prussia, or ‘Frederick the Great’, was born in 1712 and was King of Prussia from 1740 to 1786. Prof Kohl said: “The letter tells us about the importance of Berlin brothels for the military well beyond the boundaries of the city – Frederick was stationed some 40 miles away.

“He was not yet in a position of power so couldn’t issue formal edicts, but he is confident about using established channels of communication between officers and the brothels.”

The letters can be viewed at the Bodleian until November 11 and are being published online at Oxford University’s Electronic Enlightenment project.