Have There Been Shadow Councils in Star Wars Before?

The Galactic Empire has had plenty of sinister leadership groups in both the current and old Expanded Universe canons—and as you’ll see, the one seen in The Mandalorian isn’t even the first to be called the Shadow Council. Across contemporary canon however, the Empire and the Imperial Remnant’s leadership can be tracked through four distinct administrations:
The Imperial Ruling Council, which operated under Emperor Palpatine’s auspices in the heyday of the Empire, and up to its splintering after his death at Endor
The Imperial Future Council, a scattershot collection of naval officers, financiers, and former IRC advisors that briefly existed in the wake of the Battle of Endor
The first Shadow Council, the organization that replaced the IFC before being broken up at the Battle of Jakku at the machinations of its creator, Gallius Rax
The second Shadow Council, the organization spearheaded by Moff Gideon in The Mandalorian