We need to remember, that the Hanged One, wherever we find him - and especially in the Tarot is The archetype of Odin / Wodan /Votan from the Viking pantheon.
The Vikings warred, traded and subsequently settled in most places in central Europe and also brought their language and their gods to England settling permanently in 850 in Hastings......
Odin is associated with acquiring wisdom ,- through his 2 Raven Hugin (Thought) and Munin (Memory) through wandering the lands and through hanging upside down bound by one leg from Yggdrasil the Tree of Life for 9 days and nights, sacrificing one eye to the Serpent of Wisdom who lives in the roots of Yggdrasil and from her receiving the Runes and the Power of writing and divination......
A powerful archetype like that was quickly incorporated into all different believe systems and although damned by the church, the hanged one and his Powers to receive messages in trance brought this esoteric wisdom into the Tarot where we find him among the earliest cards, nicely dressed, hanging by one leg from the tree......
I am sure there is tonns of info on Odin / Wodan on the net from many different sources.
Druids bdw predate the Vikings!
M.