वज्र
Vajra, son of Aniruddha and Usha and Krishna's great-grandson, was foremost among the few heirs who survived the Yadus' mutual destruction at Prabhasa. At SB 1.15.39, before the great departure, Yudhishthira consecrated him at Mathura as lord of the Shurasena country — as he had consecrated Parikshit at Hastinapura (SB 1.15.38). Thus the succession of both the Kuru and the Yadu lines was preserved, each through a single heir.
Śrīmad Bhāgavata Mahāpurāṇa 1.15.39 — Sanskrit Wikisource (pinned oldid=364156)
Yudhishthira installed Vajra at Mathura as lord of the Shurasenas: 'mathurayam tatha vajram shurasena-patim tatah' (SB 1.15.39) — the surviving heir of the Yadu line. Evidence: EXPLICIT.
