Abstract
We present some results on our investigations on the young stellar populations in the regions DR15 and DR21 in the Cygnus-X massive star formation complex. We provide some insight on processes associated with the presence or absence of massive stars, and the consequences this has on gas removal and early evolution of young clusters. Our use of multi-wavelength data permits to define a clear picture of the recent history of the complexes and the interaction of the young stars with their local environment.
