In this talk I will present a detailed analysis of star-forming galaxies and their host dark matter halo environments over cosmic time using galaxy clustering. The deep near-infrared narrow-band survey HiZELS has yielded identically-selected samples of Ha emitters at 3 epochs spanning the decline of the cosmic star formation rate density (z=0.8, z=1.5 and z=2.2). Narrow-band samples have well-defined redshift distributions and are therefore ideal for clustering analyses. We probe the clustering of typical star-forming galaxies on and above the main sequence back ~11Gyr. At individual epochs, our samples are large enough to bin by both star formation rate and stellar mass. Fitting two-point correlation functions with sophisticated dark matter halo models, we constrain effective halo masses and central/satellite fractions as a function of star formation rate, stellar mass and cosmic epoch. Typical Ha-emitting galaxies in the redshift range z = 0.8-2.2 are star-forming centrals, residing in host halos of mass ~10^12M_sun. We find a strong, redshift-independent relationship between scaled galaxy luminosity L(Ha)/L*(Ha) and dark matter halo mass. Our results reveal halo environment as a strong driver of galaxy star-formation rate and the evolution of the luminosity function over cosmic time.