From Warhammer 40k - Lexicanum
Ymmâ's Shield is a relic of the Leagues of Votann.
It is said that the ore used in the forging of this shield was brought across the gulfs of space by the First Ancestors. Nothing has been seen before or since, though the Kin have searched desperately for the material. It fell to the venerated Brokhyr Ymmâ the Sure to fashion the unique material into a RAM Shield of unsurpassed resilience and perfect balance.
- 1: Codex: Leagues of Votann, pg. 67