Ally is the illegitimate son of the Puck, Robin Goodfellow (he was named "Ally" because he was conceived during a one-night-stand in an ally). While he was growing up, Goodfellow would visit him in dreams. Ally could not remember these dreams while he was awake, thus preventing him from remembering his parentage and the existence of faerie courts. It was in these dreams that Goodfellow taught Ally to master the fiddle.
While living in Australia, he met NattyNewlyn, who was in town from Ireland to attend a wedding. They fell in love quickly, resulting in Ally having to repeatedly defend himself from the faerie lord who was pursuing Natty at the time. When Natty returned to her home in Ireland, Ally followed her there shortly afterwards.