Urgyenpa
Urgyenpa already knew how to meditate while he was still a child. It is said that he was an emanation of Rechungpa and Khorlo Demchog. Despite this natural gift, he decided to study philosophy before beginning a serious meditation practice.
He was very headstrong, which meant that he only succeeded in making the transition from being a scholar to becoming a tantric practitioner late in life. He is known for his incredibly long journeys on foot, which he undertook to receive all the teachings he was able to.
It is said that Urgyenpa was obsessed with finding Shambala because he thought that only there could he realize the ultimate meaning of Kalachakra.
Only very late - at the age of 53 - did he meet the 2nd Karmapa, who gave him the Kagyü lineage transmissions and thus made him the next lineage holder.