Lasing on the $D_1$ transition $(6{}^{2}P_{1∕2}\to 6{}^{2}S_{1∕2})$ of Cs has been observed by photoassociating Cs–Kr atomic pairs with a tunable, pulsed dye laser. Pumping of the blue or red satellites of the Cs $D_2$ line $(6{}^{2}P_{3∕2}\leftrightarrows 6{}^{2}S_{1∕2})$ , peaking at $\sim 841.1\mathrm{nm}$ and $\sim 853\mathrm{nm}$ (respectively) in $\mathrm{Cs}∕\mathrm{Kr}∕{\mathrm{C}}_2{\mathrm{H}}_6$ gas mixtures, provides a photodissociation laser in which the CsKr excimer parent molecule is not, at any point in the pumping process, in a bound electronic state. Relative to the absorbed pump pulse energy, laser slope efficiencies $\gtrsim 5\%$ have been measured when the Cs number density is in the range of $5\times {10}^{14}–1.5\times {10}^{15}{\mathrm{cm}}^{-3}$ and the pump wavelength is $841.1\mathrm{nm}$ . Direct photoexcitation of the Cs $6{}^{2}P_{3∕2}$ state at $852.1\mathrm{nm}$ under these conditions is a less efficient pathway for pumping the $894.3\mathrm{nm}$ laser, presumably as a result of competing nonlinear optical processes such as $1+2$ resonantly enhanced multiphoton ionization of the alkali atom.