What demands for reparation have been made: The return of the Benin Bronzes

By whom: Federal Government of Nigeria

For what historical harms:

• The artifacts were stolen during the 1897 British "Punitive Expedition" against the Kingdom of Benin, The stolen items were then sold or auctioned off to museums and private collectors across Europe and North America.

In what arenas demands have been made (courts, policymaking, public protests, unclear..)

• Policymaking & Bilateral Diplomacy: Formal state-to-state diplomatic requests submitted by Nigeria to Western governments and state-run institutions.
  

How these demands have fared:

• The Netherlands handed them over wince they have an unconditional return policy for explicitly looted artifacts, bypassing roadblocks.
• United States returns happen voluntarily on a painstaking, museum-by-museum basis.
• United Kingdom: The British Museum Act of 1963 explicitly prevents from legally giving away items in its collection. The UK government resists changing this law.