Type IIn supernovae (SNe IIn) result from the deaths of the most massive stars. The broad magnitude distribution of SNe IIn make these the brightest SN events ever recorded. In addition, they are the brightest SNe in the rest-frame UV which make them ideal targets for high redshift searches. I will discuss our photometric method for detecting 1.4 < z < 3.0 SNe IIn events in the CFHTLS Deep survey and present compelling photometric candidates and preliminary Keck host galaxy spectra. In addition, SNe IIn spectra exhibit extremely bright narrow emission lines as a result of the interaction between the SN ejecta and cool circumstellar material released in pre-explosion outbursts. SNe IIn emission lines remain bright for years after outburst and are above the thresholds of current 8m-class telescope sensitivities even out to z ~ 3. I will discuss our program to detect SNe IIn emission lines to confirm high redshift events and measure their energies. These data will provide the first measurements of the high redshift SNe IIn density and Type II supernova rate and provide constraints on the high redshift galaxy IMF. I will conclude with a discussion of a future wide-field deep imaging campaign to photometrically detect SNe IIn candidates at 2 < z < 6 for spectroscopic follow-up using future facilities such as the TMT, GMT, and JWST.
.