Terra Mariana, comprising present-day Estonia and Latvia, was established as a principality of the Holy Roman Empire. Terra Mariana: Terra Mariana was the formal name for Medieval Livonia or Old Livonia. It was formed in the aftermath of the Livonian Crusade, and its territories were composed of present-day Estonia and Latvia. It was established on 2 February 1207, as a principality of the Holy Roman Empire, and lost this status in 1215 when Pope Innocent III proclaimed it as directly subject to the Holy See. February 2, 1207. Wiki link