He was the Count of Saarbrücken (de) and Seigneur (lord) of Commercy (fr), as Jean IV of Saarbrücken-Commercy, part "Château bas".
His mother was Marguerite of Savoy-Vaud (d. 1313), a daughter of Louis I of Vaud, married with Simon in 1309.
Like his father Simon, John II supported France in the war against England.
John II undertook several diplomatic missions in the service of the French King.
Various lines of the House of Nassau would hold the county until it was conquered by France in 1795.