Treaty of Tsarskoye Selo
The Treaty of Tsarskoye Selo (Danish: Traktaten i Zarskoje Selo, Russian: Царскосельский договор) also called Mageskiftetraktaten in Danish, was a territorial and dynastic treaty between the Russian Empire and Denmark–Norway. Signed on 1 June 1773, it transferred control of ducal Schleswig-Holstein to the Danish crown in return for Russian control of the County of Oldenburg and adjacent lands within the Holy Roman Empire.