The order of precedence for members of the Sejm (parliament) of the Polish–Lithuanian Commonwealth was created at the same time as the Commonwealth itself – at the Lublin Sejm in 1569. The Commonwealth was a union, in existence from 1569 to 1795, of two constituent nations: the Crown of the Kingdom of Poland (commonly known as Korona, or "the Crown") and the Grand Duchy of Lithuania. The union's legislative power was vested in a diet (assembly) known as the Sejm which consisted of the three Estates of the Sejm: the monarch, holding the titles of King of Poland and Grand Duke of Lithuania; the Senate; and the House of Deputies.