Cosmological photons as relics from the decoupling era in the childhood of the Universe were predicted in 1948 and detected in 1965. However, light has played a role in the history of cosmology at a much earlier date, first in a speculative sense and later in a more scientific context. The paper offers an incomplete survey of some of these early attempts to integrate light into cosmology. Of particular interest is a paper of 1945, written by J.B.S. Haldane, which includes what is probably the first suggestion of a radiation-dominated early Universe.

PACS numbers: 01.65.+g, 14.70.Ph