Massive stars exert a profound influence on the chemical evolution and energetics of the inter-stellar medium on a galactic scale. In an effort to uncover the details of their formation process, which remain enigmatic, we have previously isolated a sample of massive star forming regions in a very early stage of evolution. I will present a multi-wavelength observational study to derive the physical properties of the molecular gas, ionised gas and (proto)stellar content within these regions. The aim of this study is to determine the relative ages of the observed cores from a combination of their physical properties and their association with various star-formation tracers, and hence place them in a potential evolutionary sequence.