The paper offers an account of how the meaning of the concept of “invention” and “inventorship” is not stable and predefined but rather constructed during patent disputes. In particular, I look at how that construction takes place in adversarial settings like the courts of law. I argue that key notions of intellectual property law like invention and inventorship are as constructed as technoscientific claims are in laboratories. Courts should thus be seen as sites of construction through processes framed by specific (...) discursive and evidentiary technologies like bureaucratic paperwork, literary technologies, historiographic accounts of inventorship, and models of artifacts and devices. I draw my examples from the British disputes of the Marconi Company concerning the patenting of wireless telegraph and radio communication technologies in the first half of the twentieth century. The paper tracks Marconi’s circulation of publications, models, historical reconstruction of inventions, and expert witnessing. It unravels the material, discursive, textual, and evidentiary constructions of legality. (shrink)