For Thomas, who has stood on all three steps of the podium on the Champs Elysees including top spot in 2018, it is a realisation of a dream.
The Tour that inspired him to start cycling as a child will pass through the streets were he grew up, beside the cycling track where his potential was first spotted and even past is local pub.
But as well as the sporting and personal significance, the former Olympic champion is all too aware of the huge opportunities that await.
The 39-year-old spoke of showcasing Wales and the “once in a lifetime” chance to both inspire future stars and inject impetus into the tourism sector.
First minister Morgan added: “It’s a real opportunity. The eyes of the world will be on our country for one of the biggest sporting audiences on the planet.
“Millions upon millions of people around the world will never have seen parts of Wales that we’ll be showing them.
“This isn’t just a milestone for cycling in Wales, but it’s a celebration and an opportunity for us to show off our nation.”
The Tour’s general director, Christian Prudhomme, said his first taste of Wales came with rugby before Thomas rivalled the red shirt with a yellow jersey.
“The Grand Depart is always massive and we have to often explain to the French people why we go outside of France,” said Prudhomme.
“But it is because we find passion and we know it will be a resounding success in Great Britain. Wales is made for bikes.”