At the end of their Gamescom livestream, a surprise was unveiled onto fans as Age Of Empires IV was formally announced by Relic Entertainment and Microsoft Studios. The stream's primary goal was to celebrate the game's anniversary, along with announcing that Age Of Empires II and III would be getting definitive editions like the first game is getting in October. The news that a fourth game in the series would be coming was a shock that blew many in attendance away.
There's nothing much to show in the trailer below beyond the announcement news, but it's interesting to see that Relic hasn't given up on Age Of Empires as a series, as many speculate that the definitive edition would be a signaling of the end for the series as the company moved onto new projects. No official release information was given out either, so at best, we probably won't see anything concrete for the game until probably E3 2018. For now, here's the Age Of Empires IV trailer.