Complex sentence: After a series of league mergers and folds, the Cup became the "de facto" championship trophy of the NHL in 1926 and then the "de jure" NHL championship prize in 1947.
Split into simpler sentences: After a series of league mergers and folds, the Cup became the "de facto" championship trophy of the NHL in 1926. The Cup became the "de jure" NHL championship prize in 1947.