Editorial note to : H . P . Robertson , Relativistic cosmology

Such models had been initiated by Einstein’s 1917 paper [12] on the Einstein static solution,1 and then developed by a small group of pioneers: Einstein, de Sitter, Friedmann, Lanczos, Weyl, Lemaître, Robertson, Tolman, and Eddington. A second wave of pioneers—von Laue, Heckmann, McCrea, McVittie, Whittaker, Ward, Milne, and Walker2—joined in after the idea of an expanding universe became accepted in 1931, providing a sound theoretical basis forHubble’s observations of themagnitude-redshift relation for galaxies. Robertson’s article was written 16years after the first General Relativistic cosmological model and 11years after the first expanding universe models