Jasper was the eldest son of the late King of Portal City, and took over the city when he died. He married Sallix, a lady from a distant land, and proceeded to pass several very unpopular new laws. He had two siblings, a girl Acara and a boy Wocky.
It is unknown why Jasper retains the title of Prince despite technically being a King, nor why his wife holds the title of Queen.
As Jasper only appears in Katya's tale, it is unclear if he ever really existed.