Secret treaty of Dover

The Treaty of Dover, also known as the Secret Treaty of Dover, was a treaty between England and France signed at Dover on 1 June 1670. It required France to assist England in the king's aim that it would rejoin the Roman Catholic Church and England to assist France in its war of conquest against the Dutch Republic. The Third Anglo-Dutch War was a direct consequence of this treaty.

Exactly who first proposed the alliance between the two kingdoms is unknown, as is the date when the possibility was first discussed. However, it is known that the two nations had discussed forming a closer relationship since 1663. The only participants in the talks to begin with were Louis XIV of France, Charles II of England, and Charles's sister Henrietta, duchesse d'Orléans. Louis was first cousin to Charles (through their grandfather Henry IV of France). Henrietta was also Louis's sister-in-law through her marriage to his only brother Phillippe, duc d'Orléans.

No real progress was made in the negotiations until 1669 after Charles allegedly held a meeting with some of his advisors. During this meeting Charles announced that he wished to officially convert to Catholicism and at the same time reunite his lands with the Roman Catholic Church. Whether this meeting actually took place is a source of intense speculation. Although much of the groundwork had been laid by Henrietta, the finer points and actual provisions of the treaty were hammered out by Henry Bennet, 1st Earl of Arlington and Sir Thomas Clifford.

Charles was to abandon England's Triple Alliance with Sweden and the Dutch Republic in favour of assisting Louis in conquering the Dutch Republic. Provided that the conquest was successfully completed, England was promised several very profitable ports along one of the major rivers that run through the Dutch Republic. In particular, the main components of the treaty were the following:

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