Contemporary Buddhist nationalist discourse in Burma turns to history to construct Buddhist identity as unchanging and embattled. Drawing on mid 20th century history writing practices, the past becomes the source of stability and facticity for claims about Burmese Buddhism under threat from religious and national others. The most devastating instance of this is the ways in which the legitimacy and political future of the Rohingya relies on history to prove the presence of their ancestors inside or outside the imagined borders of the Burmese empire prior to the arrival of the British. This paper looks at two key elements of contemporary Burmese Buddhist nationalist discourse that became established facts through 20th century Burmese history writing: a particular telling of the entwined co-emergence of modern Buddhism and Burmese nationalism and an oft repeated fear that “A Landslide does not Submerge a Race, but Another Race Does!” I examine how Burmese approaches to history writing in the 20th century endowed what in both cases appeared first as assertions of contested positions in debates over Burmese pluralism of the 1920s with fixity and facticity in the mid 20th century enabling them to become political weapons in the 21st century.