Arnold Joost van Keppel was born in Zutphen in the Dutch Republic about 1670 and was the heir of a junior branch of an ancient and noble family in Gelderland. He achieved fame and wealth as the right-hand man of William III of Orange. He became page of honour to William III in his mid-teens, possibly as early as 1685. It has been claimed that he was William's lover, but no conclusive evidence has been discovered. Keppel accompanied William to England in the Glorious Revolution of 1688.