Today's clue from the New York Times crossword puzzle is : Belgium's longest-reigning monarch (44 years) First let's look and see if we can find any hints in the New York Times crossword puzzle. Then we will gather any relevent information we need in order to find the correct answer to the clue Belgium's longest-reigning monarch (44 years) that has been given in the New York Times crossword puzzle. Finally we will list any possible answers here below for the clue Belgium's longest-reigning monarch (44 years).