Nigeria, June 4 -- King Mswati III is basking in infrastructure development as he marks 40 years on the throne in eSwatini, a landlocked kingdom of 1.5 million people. Cheers are flowing in. Blue chips, from Standard Bank to Nedbank, and the region's top brass, are singing the king's praises. Dejected activists, some of who now live in exile, look on helplessly, struggling to re-claim the discourse even as regional leaders throw their weight behind the king.

The kingdom's two-day jamboree gathered thousands at a tiny and old Somhlolo stadium, then, with Southern Africa's finest as guests, moved to Mbabane's spanking new International Convention Centre (ICC). Colour, pomp and song defined the moment.

Lesotho's King Letsie III, along with...