In this federation , the Grand Duchy of Lithuania maintained its political distinctiveness and had a separate government , laws , army , and treasury This federation was terminated by the passing of the Constitution of May 3 , 1791 , and since then there was supposed to be but a single country - Respublica Poloniae - under one monarch and one parliament .
In this federation , the Grand Duchy of Lithuania had a separate government , laws , army , and treasury .