In some ways, it was a win against the odds, given the number of politicians against the project. Even Theresa May expressed opposition in 2009, saying many in her constituency would be "devastated" by it.
Why did Heathrow succeed? Some commentators pointed to its case for economic benefits of the expansion, which helped win the crucial backing of Airports Commission chairman Sir Howard Davies.
Heathrow was criticised for funding the 'grass-roots' campaign Back Heathrow, but mobilised public support (a 2015 consultation by the Airports Commission found 82 per cent backed expansion).
In contrast, Gatwick’s bid was criticised for focusing on the downside of Heathrow expansion, which, while of great significance in the region, resonated less strongly elsewhere.
Heathrow ratcheted up its campaign after the EU Referendum, saying on the eve of the Conservative Party Conference it would bring the benefits of expansion four years early in a £1.5bn "Brexit boost".
Campaigning will continue, with challenges expected. But for now, the airport and its PR and lobbying associates will give themselves a pat on the back.