Following war with the Dutch in 1665, during which the English Naval fleet was all but destroyed. Fearing this would leave England in a vulnerable state, and open to invasion by France, Charles II approached the French King, his cousin Louis XIV, to negotiate an alliance.
Using his sister, Henrietta, who was married to Louis’ brother Philippe, Duc d’Orleans, as a negotiator, Charles agreed a secret treaty, whereby he would convert and declare himself a Catholic, at a date convenient to Charles, and assist Louis in a war against the Dutch, in return for an annual pension and a lump sum payment.
Charles bought himself time for the conversion, explaining that the English Protestants would be suspicious of a return to the Catholic faith and would use this as an excuse to overthrow the throne. The money, around 2 million crowns, he used mainly to bribe the ministers needed to countersign the terms including Henry Bennet, 1st Earl of Arlington, and quite probably Sir Thomas Clifford.
The treaty was drawn up and dispatched with the Duke of Buckingham to get Louis’ signature, meanwhile a second, public treaty was drawn up, omitting the clauses concerning the Catholic conversion and the proposed war with the Dutch. Other terms included that the conquered lands would be taken under France with strategic Ports through the Dutch Republic placed in English hands with all profits from trade and commerce to divert to the English purse.
The treaty went smoothly, signed on 1st June 1670, at Dover. The second treaty was signed by the five members of the Cabal Ministry In the following December. Unfortunately the proposed war did not go off as smoothly, Declared by Louis on 6th April 1672 and the following day by Charles, the costs to deploy the Navy were greater than expected and not covered by the funds Louis had supplied for the purpose. Forced to call Parliament into session for the first time in two years, to try for additional finance, Charles was eventually forced by Parliament to withdraw from what was subsequently known as the Third Anglo-Dutch War with the Treaty of Westminster, in 1674. This ended England’s chance of becoming reunited with the Roman Catholic Church.
Charles however, converted on his deathbed to the Catholic faith.