We celebrate the 100th anniversary of the expeditions by Eddington, Dyson, and colleagues to Principe and Brazil to carry out the observations that verified the predictions of Albert Einstein using his new General Theory of Relativity. The eclipse was on 29 May 1919 and the announcement of the successful verification at a joint meeting of the Royal Society and the Royal Astronomical Society in London on 6 November 1919 changed the course of science and made Einstein an international celebrity, even though the general public did not understand the result. Our session includes two experts on the observations from Principe and Brazil and their subsequent analysis and reanalysis. Also, two colleagues describe the centennial activities on Principe and elsewhere.

Additional papers relevant to the topic would be presented as posters.