In the 1720 Treaty of The Hague, Spain renounced its Italian possessions, in return for a guarantee Parma would go to Elisabeth's eldest son Charles on the death of the childless Duke of Parma. The new British monarch, George I, agreed to raise the question of returning Gibraltar in Parliament 'at a favourable opportunity.' Frustration at the lack of progress on this and commercial tensions led to the 1727 to 1729 Anglo-Spanish War.