The Mark of Passage first manifested 1900 years ago in what is now Aundair. It wasn't the first dragonmark to manifest (it wasn't even the first to manifest on humans), but its arrival was nevertheless significant. The families that manifested it converged over the next few centuries, forming an alliance led by Orien Bayne, which would eventually come to be known as House Orien.
The Mark of Passage causes a restlessness in its bearers, a need to move. They were never able to stay still and remain in one place, their mark drives them to travel, and this has shaped the way the House has grown. The Mark makes its bearers supernaturally fast, and some can even teleport. it is required to operate the Lightning Rail or Elemental Land Carts, and most of the roads on Khorvaire carry enchantments that activate when the Mark of Passage is present on them, speeding those with it along.