"This is the first complete English translation oft he fourth chapter oft he Buddhist Kalacakra Tantra text and its commentary, the Stainless Light. Building upon the Chapter on the Cosmos which provide the theoretical background to the Chapter on Sadhana, and the reasons for the given structure and contents of the Kalacakra sadhana practic--this fourth chapter illuminates the intricate connection between the practice o f the Kalacakra sadhana and the Kalacakra Tantra's worldview. This fourth chapter describes Buddhist Tantric generation stage practices including instructions on protecting the place of practice, the meditative practices of the origination of the body and the deities abiding in the body, and the diverse mundane sadhanas designed to induce the mundane siddhis. It then also describes the more advanced Buddhist Tantric completion stage practices designed to lead directly to the attainment of buddhahood, called here the "Adibuddha" (Primordial Buddha).