The news aimed to hurt and the timing couldn't have been blunter. As the 14th Francophonia Summit is about to open in Congo's Kinshasa, in the presence of French president François Hollande, its neighbour Gabon has just announced that it was striking off French as its official language. Ouch. Ouille. And has Gabon chosen to adopt Baka instead, one of its people's many dialects? Not quite. Gabon is adopting English as its official language. Argh, that's what you call a double blow. I was sitting in a cafe in Paris when I heard the news and, even from there, Gabon's choice feels, not like a slap in the face, more like being spurned by your first love, deeper, and more painful.

Like Rwanda in 2009, which dropped French, adopting English instead and even joining the Commonwealth, here is another African country using language as a political weapon, a declaration of war even, albeit a pacific one. Like Rwanda, Gabon intends to show its seething rage at France. This time, it is not the French army's alleged exactions that Gabon is revolting against but rather French justice's actions.

After decades of France turning a blind eye on the Bongo family's luxury acquisitions in France, no doubt in exchange of advantageous business partnerships, French justice has recently decided to look more closely at Gabon's first family's assets in France, at the request of two anti-corruption NGOs. Investigators uncovered, in their own words, "the cave of Ali Baba" and discovered among others, a family portfolio of 33 luxury properties alongside 70 different bank accounts. All of which are alleged to have been funded directly from Gabon's treasury. This ongoing judicial investigation is known as the ill-gotten gains scandal and French magistrates are now also looking at other African presidential families' assets such as the Congo's Sassou Nguessos, Equatorial Guinea's Obiang Nguema Mbasogos, and Burkina Fasso's Compaorés. Some properties and whole fleets of luxury cars belonging to the Bongos and other African first families have been seized by French justice. Needless to say, the inquiry has sent shockwaves through diplomatic circles and that bilateral relations between Paris and some African capitals have become very tense as a result.

No doubt the gathering tomorrow in Kinshasa of the 56 French-speaking countries will feel slightly less crowded and the summit's secretaries will be able to subtract Gabon's 1.5 million inhabitants from the 220m strong Francophone world. But will the Bongos rebaptise their country's capital Libreville as Freetown (also Sierra Leone's capital city)? Will Libreville's rue d'Alsace Lorraine become Essex street and its "Le Petit Paris" district "The Little London"? History will tell. In the meantime, Adieu, ami Gabon!

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