If you aren’t up on your Star Wars lore a significant part of the Mandalorian finale might have passed you by.
During the end of Redemption, Moff Gideon’s Outland TIE fighter comes crashing out of the sky courtesy of the Mandalorian. When Gideon extricates himself from the wreckage he does so with a very strange looking lightsaber.
That lightsaber is a very important part of Mandalorian history.
As explained in both the Star Wars: Clone Wars and Star Wars Rebels animated series, the Darksaber was created by the first Mandalorian to become a Jedi: Tarre Vizsla.

To make a long story short, the saber fell into the hands of Death Watch, a militant group who opposed the pacifist government of Mandalore. Eventually, Darth Maul killed the leader of Death Watch, became their new leader and took possession of the Darksaber. It became his weapon of choice.
Mandalorian rebel Sabine Wren recovered the Darksaber and was trained in its use. When the Mandalorians took up arms against the Empire, Wren passed the Darksaber and the leadership role to Bo-Katan Kryze. From that point forward in order to claim the blade one had to defeat the owner in combat.
How such an important, historic Mandalorian artifact came into the possession of Moff Gideon is unknown.
Top Photo: Moff Gideon wields the darksaber at the conclusion of episode eight of The Mandalorian. Courtesy: Disney+.