Historians in Nordic countries since the turn of the twentieth century have become increasingly aware of the problem using these primary sources from earlier times, especially the sagas from the late twelfth- and thirteenth centuries, about three hundred years after Harald assumedly lived. It was Halvdan Koht(1873-1965)who introduced this point of view into Norwegian historiography, although some researchers, including Yngvar Nielsen, had cast doubt on the accuracy of the account before him.