Clifford Will is the Editor-in-Chief of Classical and Quantum Gravity, Distinguished Professor of Physics at the University of Florida, Chercheur Associé at the Institut d’Astrophysique de Paris, and James McDonnell Professor of Space Sciences Emeritus at Washington University in St. Louis.

November 4, 1915 was a Thursday. It was the day that Albert Einstein gave the first of a series of four weekly lectures to the Prussian Academy of Sciences in Berlin. His life was a mess. He was separated from his wife Mileva, who had moved to Zurich taking his sons with her. He was having an affair with his second cousin Elsa. He was working night and day, was barely eating, and was suffering from stomach pains. He had agreed to give these lectures to present his theory of gravity but he still didn’t have it. To make matters worse, David Hilbert was racing to find the field equations first, and Einstein feared he would be beaten. Yet by the third lecture, he had settled on the field equations and checked that they gave the correct perihelion advance for Mercury, and in the final lecture of November 25, he presented the field equations of general relativity.

This year, gravitational physicists around the world are celebrating the 100th anniversary of this great achievement, with conferences, books, lectures and outreach. CQG is also joining the celebration, with two special focus issues. Milestones of General Relativity presents 11 specially commissioned articles on major events that occurred during the past century, beginning with Eddington’s 1919 measurement of the deflection of starlight, which made Einstein and his theory international celebrities, and ending with the 2005 breakthrough in numerical relativity for the binary black-hole problem.

This month we present Gravity Probe-B, consisting of 21 refereed papers giving full scientific and instrumental details of that remarkable space experiment to measure the general relativistic dragging of inertial frames.

In a certain sense, we at CQG celebrate general relativity every year, as we strive continually to publish the highest quality papers in gravitational physics. To see what the CQG Editorial Board thinks are the best papers for the year ending around May 2015, check out the CQG Highlights.