He was essentially hidden away at the Chantry by age ten, but actually has some sort of claim on the throne (though he doesn't seem at all interested in pursuing it). As the conversation winds, you'll learn that the king was his father, and that his mother was a servant. Alistair has something to tell you, and it's that he knows the Arl of Redcliffe because he was raised by him. At Redcliffe, Alistair will stop the party and engage you in an important conversation before you regain control. When you're done, head back to the world map, and the game will bring you the rest of the way to Redcliffe itself. He's got some stuff you may just want to buy. He won't be too forthcoming with information about Orzammar's plight if you pick his brain, but be sure to look at his goods. Speak with him, and he'll tell you he's selling his wares at a discount, and that there's trouble brewing in the dwarf stronghold of Orzammar. The real point of interest here is Old Tegrin, the dwarven merchant, and his cart that's blocking the road. This area can't be explored too thoroughly, though you'll find an Elfroot if you search for a moment. En route, you'll encounter a wagon in your path.

You can access Redcliffe, just like any other location, from the world map. Though you can go to four locations from Lothering, in any order you want, we've decided to head to Redcliffe first. Defending Redcliffe | Redcliffe (Daytime, I)

Dragon age origins redcliffe