Disputed discovery: the beginnings of X-ray diffraction in crystals in 1912 and its repercussions.

The discovery of X-ray diffraction is reviewed from the perspective of the contemporary knowledge in 1912 about the nature of X-rays. Laue's inspiration that led to the experiments by Friedrich and Knipping in Sommerfeld's institute was based on erroneous expectations. The ensuing discoveries of the Braggs clarified the phenomenon (although they, too, emerged from dubious assumptions about the nature of X-rays). The early misapprehensions had no impact on the Nobel Prizes to Laue in 1914 and the Braggs in 1915; but when the prizes were finally awarded after the war, the circumstances of `Laue's discovery' gave rise to repercussions. Many years later, they resulted in a dispute about the `myths of origins' of the community of crystallographers.