The Chronicle of The Kings of Norway
Part 211 - Of King Olaf's Journey
King Olaf sent a message before him to all the inhabited places he passed through, that the men who wished to get goods and money, and share of booty, and the lands besides which now were in the hands of his enemies, should come to him, and follow him.
Thereafter King Olaf led his army through forests, often over desert moors, and often over large lakes; and they dragged, or carried the boats, from lake to lake. On the way a great many followers joined the king, partly forest settlers, partly vagabonds. The places at which he halted for the night are since called Olaf's Booths.
He proceeded without any break upon his journey until he came to Jamtaland, from which he marched north over the keel or ridge of the land. The men spread themselves over the hamlets, and proceeded, much scattered, so long as no enemy was expected; but always, when so dispersed, the Northmen accompanied the king. Dag proceeded with his men on another line of march, and the Swedes on a third with their troop.