The Rigdens

The eighth in Dawa Sangpo’s line, Yasas, an emanation of Manjushri, also received the Kalachakra lineage and taught the tantra for one hundred years. As his reign was drawing to a close, King Yasas foresaw that the Shambhala Kingdom would become vulnerable to barbarian invasion due to the continued adherence of his subjects to divisive caste identities and to sacrificial ritual practices. Yasas gathered the Brahmanic lords from throughout the kingdom and requested them to take initiation in the Kalachakra, and to put aside caste identity to come together as one “Vajra Caste.” The lords eventually agreed, dissolving caste and clan distinctions and abandoning Vedic rituals.

Having achieved the unification of all Shambhala under one vajra clan, Yasas became known as the first Kalki King (Rigden in Tibetan). In Tibetan, rig (usually transliterated as rigs) means “family,” “caste” or “kind,” while den (from dang ldan pa) means “endowed with” or “holding.” So Rigden literally means “endowed with family” or “holder of the lineage,” a name representing the bringing together of all castes, clans and religious systems of Shambhala into one.

Rigden Yasas was the first of the twenty-five Rigden Kings that the text predicts will reign in Shambhala. Tibetan commentators have calculated that the twenty-fifth Rigden, Raudra, will begin his reign in the year 2327 CE. The Kalachakra predicts that the twenty-fifth Rigden will go into battle against barbarian forces, re-establishing the dharma throughout the world in his victory.

Source

{https://shambhalatimes.org/2018/10/28/shambhala-in-the-kalachakra-tantra/}