It is possible that more Middle Irish literature was written in medieval Scotland than is often thought, but has not survived because the Gaelic literary establishment of eastern Scotland died out before the fourteenth century. Thomas Owen Clancy has argued that the "Lebor Bretnach", the so-called "Irish Nennius", was written in Scotland, and probably at the monastery in Abernethy, but this text survives only from manuscripts preserved in Ireland. Other literary work that has survived includes that of the prolific poet Gille Brighde Albanach. About 1218, Gille Brighde wrote a poem—"Heading for Damietta"—on his experiences of the Fifth Crusade.