14th century, in the meaning defined at sense 114th century, in the meaning defined above

Middle English desolat, desolate "deserted, lonely, distressed," borrowed from Latin dēsōlātus, past participle of dēsōlāre "to leave all alone, forsake, empty of inhabitants," from dē- de- + -sōlāre, verbal derivative of sōlus "lone, acting without a partner, lonely, deserted," of uncertain originMiddle English desolaten (in past participle desolatid "deserted, ruined"), borrowed from Latin dēsōlātus, past participle of dēsōlāre "to leave all alone, forsake, empty of inhabitants" — more at desolate entry 1