Canon Background
https://awoiaf.westeros.org/index.php/Yoren

In-Campaign
It was February of 288AC and Yoren was on his first recruiting trip as a wandering crow in The Vale. He was north of Ironoaks when a young man, aged ten-and-six, slipped his bonds and absconded. Ser Darron, Ser Dolins, and Gregoriy happened by not long after, on their way to the Spring Tourney at The Gates of the Moon. Yoren asked for aid, which the travelers granted. The trio set off in search of a young man called Wine, whom they located and returned with. However, instead of sending the lad to the Wall with Yoren, Darron donated 1gd to the Nights Watch so that the youth could become his squire.