The lecture course will provide an introduction to quantum field theory from a different perspective than usual: Rather than starting from a modern formulation, focusing on the calculation of scattering matrix elements and Feynman graphs, the course will take as its starting point non-relativistic quantum mechanics and follow the historical transformation of this theory from 1927 to 1950, when the modern renormalized formulation of quantum field theory was first established by Feynman and others. The course will thus provide both an introduction to the history of quantum field theory and an introduction to the theory itself, where the emphasis is placed on the essential similarities and differences between quantum field theory and the quantum mechanics that the students know from their introductory theory courses. In the accompanying tutorial class we will be reading (and working through the calculations in) some of the essential founding papers of quantum field theory by Jordan, Pauli, Dirac, Tomonaga, Feynman, Dyson, and others. This is the only literature used in the course and it will be fully provided by the lecturer.