The advent of oxygenic photosynthesis in cyanobacteria more than 2.4 billion years ago triggered dramatic changes in Earth’s geochemistry and biosphere. The most momentous was the resulting rise in the level of molecular oxygen in the atmosphere. The initial chemical reaction in oxygenic photosynthesis is the extraction of electrons from water; these electrons then fuel the photosynthetic electron-transport chain, generating the chemical energy carriers NADPH and ATP. The photosynthetic electron-transport constituents are associated with a specialized membrane system known as the thylakoids and include the photosystem I and II (PSI and PSII, respectively) multisubunit protein/pigment complexes and the cytochrome (cyt) b6f complex, the structures of which have recently been resolved at atomic resolution. However, as compared to that, relatively little is known about how these complexes are put together during the development of the thylakoid membrane (TM) system. The goal of our work is to dismantle the molecular details of the biogenesis process of thylakoid membranes. This includes the identification and characterization of factors controlling the synthesis and assembly of photosynthetic complexes as well as the cytological organization of the biogenesis process.