Caracalla subsequently informed the Roman Senate by letter that Parthia had been defeated and was awarded the title of Parthicus Maximus, "great conqueror of Parthia", to go along with his existing titles Britannicus Maximus and Germanicus Maximus (referring to earlier campaigns in Britain and Germany).[8] The army spent the winter at Edessa, but Caracalla was assassinated on 8 April 217 while urinating at a roadside.[11] The Parthians regrouped, fighting the Romans to a bloody standstill at the Battle of Nisibis.[12] His successor, Macrinus, brought the war to an end in 218 by paying the Parthians reparations of possibly as much as 50 million denarii.[13]