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We describe results from the deepest optically identified ROSAT survey yet performed, designed to resolve as much of the soft X-ray background as possible. The ROSAT PSPC exposure of 110 ksec reaches a limiting X-ray flux of 2x10$^{-15}$ erg cm$^{-2}$ s$^{-1}$ (0.5-2 keV). At this flux limit we have currently optically identified a total of 84 sources, representing 82\% completeness. At relatively bright fluxes ($>$10$^{-14}$ erg cm$^{-2}$ s$^{-1}$) QSOs dominate the survey. However below a flux of 5x10$^{-15}$ erg cm$^{-2}$ s$^{-1}$ a population of narrow emission line galaxies dominates. The number counts of these faint galaxies rise steeply at faint X-ray fluxes and they are clearly a major new contributor to the X-ray background. They contribute 9-20\% of the X-ray background at our flux limit. Optical emission line diagnostics indicate that they are a mixture of Sy2 galaxies, possible starburst galaxies and relatively normal galaxies at their redshifts of z$\approx$0.2-0.5.
