Ernest Shackleton

Anglo-Irish polar explorer — famous for the failed but heroic Endurance expedition (1914–16), where his ship was crushed in Antarctic ice and he led all 28 crew members to survival across 800 miles of open ocean in a lifeboat.

Provides the canonical example of leadership under existential crisis — Shackleton's Endurance expedition (no ship, no rescue possible, two years stranded) and his 100% survival rate for his crew is the most studied natural experiment in crisis leadership.