Where/when was this picture taken?

The picture in question is this: http://abstrusegoose.com/images/brilliant.JPG

Quite a lineup. Hendrik Lorentz looks so ancient! The caption says it was taken in Brussels, but nothing else. What was this event?

1927 Solvay Conference on Quantum Mechanics in Brussels
Wiki Entry

As an aside, has there even been a greater assemblage of scientific (i.e. physics) genius in such a small, well-defined area before or since? I doubt it. A list of the names of the people in the picture reads like a who’s who of the greatest Nobel laureates of 20th century physics. Indeed, the greatest physicists of any century:

Einstein, Bohr, Curie, Planck, Dirac, deBroglie, Lorentz, Bragg, Pauli, Heisenberg, Schrödinger, Richardson, Langevin, Born, Compton . . . All in one place. At one time. It boggles the mind.

Thanks for the answer!

Karl, I was thinking the same thing. Really a staggering collection of people. I can’t imagine there’s been a greater concentration of genius.