Chagos Islands treaty signed: UK hands sovereignty to Mauritius
Why in the news
The UK and Mauritius formally signed a treaty on 22 May 2025 under which the UK gives up sovereignty over the Chagos Archipelago. The move follows a 2019 International Court of Justice advisory opinion that pressed Britain to end its administration of the islands.
Key facts
- Sovereignty: transferred to Mauritius.
- Diego Garcia: stays under UK control for the joint UK-US military base.
- Lease: 99 years, with an option to renew for a further 40 years.
- Payment: about £101 million per year from the UK to Mauritius.
- Ratification: both parties must approve the treaty before it takes effect.
| Item | Detail |
|---|---|
| Signed | 22 May 2025 |
| Leaseback term | 99 years plus 40-year extension |
| Annual payment | About £101 million |
| ICJ advisory opinion | 2019 (February) |
About the dispute
The islands were separated from Mauritius in 1965, before Mauritius became independent in 1968, and Britain has controlled them since 1814. The 2019 ICJ opinion, though not binding, said the UK should end its administration of the archipelago as quickly as possible. India welcomed the agreement as good for regional stability.
Exam angle
- Note the Diego Garcia exception and the 99-year leaseback.
- The ICJ opinion was advisory, not binding.
- Chagos lies in the Indian Ocean; expect questions on the countries involved and the base’s role.