The history of the cosmological constant problem
  The interesting early history of the cosmological term is reviewed, beginning with its introduction by Einstein in 1917 and ending with two papers of Zel'dovich, shortly before the advent of spontaneously broken gauge theories. Beside classical aspects, I shall also mention some unpublished early remarks by Pauli on possible contributions of vacuum energies in quantum field theory. 
Norbert Straumann (Institute for Theoretical Physics, University of   Zurich, Switzerland)