The Galaxy's supermassive black hole is a hundred times closer than any other massive singularity. It is surrounded by a highly unstable gas disk so why is the black hole so peaceful at the present time? This mystery has led to a flurry of models in order to explain why Sgr A* is radiating far below (1 part in 108) the Eddington accretion limit. But has this always been so? Evidence is gathering that Sgr A* has been far more active in the recent past, on timescales of thousands of years and longer. The bipolar wind discovered by MSX, the Fermi gamma-ray bubbles, the WMAP haze, the positronium flash confirmed by INTEGRAL, are indicative of something truly spectacular in the past. But when and how did this happen? We present new evidence that the Galactic Centre was a full blown "active galaxy" just a few million years ago. We discuss the most likely scenario for this incredible event which can be seen today imprinted across the Galaxy.