Who presided over the First Buddhist Council held at Rājagṛha after the Buddha's parinirvāṇa?

Q. Who presided over the First Buddhist Council held at Rājagṛha after the Buddha's parinirvāṇa?
Answer: Mahākāśyapa
Notes: Mahākāśyapa, a principal disciple of Buddha, led the First Buddhist Council at Rājagṛha post-parinirvāṇa, standardizing teachings and monastic discipline. He is regarded as the first patriarch in Early Buddhism and associated with the Chan/Zen tradition lineage.