Tudor scholars were interested in Matilda's right of succession. According to 16th century standards, Matilda had a clear right to the English throne, and academics therefore struggled to explain why Matilda had acquiesced to her son Henry's kingship at the end of the war, rather than ruling directly herself. By the 18th century, historians such as David Hume had a much better understanding of the irregular nature of 12th century law and custom and this question became less relevant. By the 19th century, the archival sources on Matilda's life, including charters, foundation histories, and letters, were being uncovered and analysed. Historians Kate Norgate, Sir James Ramsay and J. H. Round used these to produce new, richer accounts of Matilda and the civil war; Ramsay's account, using the "Gesta Stephani", was not complimentary, while Norgate, drawing on French sources, was more neutral in tone. The German academic Oskar Rössler's 1897 biography drew heavily on German charters, not extensively used by Anglophone historians.