Dutch Sovereign William III, Prince of Orange,…

Dutch Sovereign William III, Prince of Orange, is both James's nephew and his son-in-law, and, until the birth of James's son, his wife, Mary, had been heir apparent.

William's chief concern is to check the overgrowth of French power in Europe, and he welcomes England's aid.

A letter sent by seven notable Englishmen (five Whigs and two Tories, known to posterity as the "Immortal Seven") to William, received by him on June 30, 1688, asks him, because in England a Catholic male heir had been born, to force the ruling king by military intervention to make William's Protestant wife Mary, James's eldest daughter, heir to the throne, preferably by establishing that the newborn Prince of Wales is a fraud.

The letter informs William that if he were to land in England with a small army to restore "English Liberties", the signatories and their allies would rise up and support him.

The Invitation briefly rehashes the grievances against King James, claimed that the King's son is suppositious, and offers some brief strategy on the logistics of the proposed landing of troops.

It had been carried to William in The Hague by Rear Admiral Arthur Herbert (the later Lord Torrington) disguised as a common sailor, and identified by a secret code.

William and Mary had already in April of that year, when William had started to assemble an invasion force, asked for such an invitation to be given, within the context of a secret correspondence since April 1687 between them and several leading English politicians, discussing how best to counter the pro-Catholic policies of James.

Thus, having been in close touch with the leading English malcontents for more than a year, he accepts their invitation and carries out his existing plans to land with a large Dutch army.