Occupying a large tract of the phase diagram, the pseudogap is one of the most studied aspects of cuprate superconductors. For decades the most advanced techniques have been brought to bear on the pseudogap, and yet questions remain concerning its origin, and its relation to superconductivity as a collaborator, controller, competitor or cohabiter.

Understanding the vast amount of data gathered depends on the models used to interpret it. In this talk I will demonstrate how the observed electronic, thermodynamic, transport and spectroscopic properties lead us toward a Fermi surface reconstruction model for the pseudogap state. The implications and remaining knowledge gaps will be discussed.

Keywords: Cuprates, Pseudogap, Fermi surface