Robin Marshall has been a consistent innovator in the field of high-energy electron–positron annihilation, making many personal contributions. He was the first at the PETRA e+e– collider at DESY to determine the electroweak properties of leptons and then quarks. These papers become templates for other experimenters over the next ten years. He performed the definitive analysis of the world’s electron–positron data to produce what are now the ‘text-book’ results for the QCD ‘fine structure’ constant and the fermion electroweak parameters. In 1984, he published a novel method for isolating bottom (b) quark events and then used the method to measure the b electroweak properties, showing that it belonged to a weak isospin doublet, and hence that the top (t) quark exists. This was one of the most significant physics results from PETRA. He has been a group leader at RAL since the 1980s, and in the 1990s prepared an experiment at the electron–proton collider, HERA, at DESY.