The age of consent for men in 1600's England was achieved in two stages. First came at the age of 14, this was known as the age of discretion.
Full adulthood was reached at the age of 21 years, and brought with it all the duties and privileges of adulthood. These thresholds were to set the time table royal for marriage plans

A Proposal From Spain

In the year of 1614 when Charles was close to his 14th birthday, Don Diego Sarmiento de Acuña, 1st Count of Gondomar the Spanish ambassador to England, first proposed a proposed marriage between Prince Charles and Infanta Maria Anna the daughter of Philip III of Spain. At the time this proposal was very unpopular with England's Protestant House of Commons. Charles had just reached the age of discretion (14) so there was no cause to decide quickly, so James decided let things settle down and he just postponed the decision. The Spanish, who in truth commenced the marriage negotiations originally as attempt to keep the British out of Spain's growing empire. To make England ally of Spain by marriage would effectively put an end to British competition.

A Spanish Marriage That Was Never To Be

When in 1621 Charles achieved adulthood he decided it was time to choose a wife, James decided to revive the provisional marriage agreement with Spain. The Infanta of Spain was a good potential bride for many reasons. The Catholic Howards and other ministers and diplomats enthusiastically supported the proposal. James had Sir Walter Raleigh arrested in October 29th 1618, after his return to England, after his failed attempt to raid a Spanish treasure fleet. Raleigh was tried and executed, many people at the time felt Raleigh had been sacrificed to appease the Spanish, and settle the diplomatic dispute with ambassador Gondomar. The Pope of the day Gregorio XV was in favour as he hoped it might help bring the English church back into the Catholic fold.

Charles was keen and proposed the he and George Duke of Buckingham might go to Spain and visit the Royal court and sweep the Infanta off her feet. James agreed partly because it was an attractive way to maintain peace with Spain and avoid a costly war, and partly because wedding dowry would give him funds that were not under control of Parliament, and this would afford him more political freedom.

On the 18th February 1623, Charles and George accompanied by a suitable entourage set out for Spain¹. Traveling discreetly by way of France and in an unofficial capacity using the names of John and Thomas Smith,² Charles and George arrived in almost unannounced in Madrid on the 7th March. They went straight to the residence of England's Ambassador to Spain, Sir John Digby, the 1st Earl Of Bristol. The arrival of Charles and his party was a surprise to both king Philip of Spain and the English Ambassador.

When Lord Bristol was informed of the purpose of the mission must have had some misgivings. Charles may have been alright and as befits a Pince of the realm. George even though he was newly married was however a different matter. Later events were to prove that he was attempting to cover a young man’s nature with a thin veneer of gentility.

Perhaps due to advice given by Lord Bristol on the 16th of March Charles in the company of a small retinue attended the palace. Charles paid his compliments to King of Spain now Philip IV³ and explained the purpose of his visit and presented the royal family with lavish gifts.

Charles made an excellent impression with everyone at the Spanish court except the Spanish Princess. The quest went well and may have succeeded but for the conditions set out by King Philip for the marriage of his sister. The Spanish conditions for the marriage were unacceptable to the English court. The two points that caused the most trouble were -

1. Charles had to convert to Catholicism in order to marry Infanta Maria Anna. He also had to reside in Spain as a guest of the court for one year after the marriage.
2. All Catholics in England were to be granted total religious freedom and full repeal all anti-Catholic laws.

Charles was aware the conditions were unacceptable but to avoid the stigma of failure Charles it appears he decided to allow his father the James and Parliament to make the final decision. He agreed to send home to get formal agreement to King Philips proposals from the James and the Parliament.

Charles had concluded his part of the negotiations, and settled down to await the decision of the King and Parliament. Both King James and the Parliament were furious with the Spanish proposals and further discussions were delayed due to the death of Pope Gregorio.

There is an interesting story to be found in the memoirs of Madame de Motteville, who states she talked with Henrietta Maria after she settled in Paris. This was during the English Civil war, Queen Henrietta having set up the Royalist court in exile at St-Germain-en-Laye. The story was A French princess an older sister of Henrietta Maria possibly Christine Marie, who later married the Duke of Savoy, privately met Charles and the pair spent sometime in conversation, during which she said she wish wished Charles would marry her sister. The pair spent some time in conversation regarding the matter. This conversation was thought to have influenced his choice of wife.

Negotiations were brought to an abrupt end when a drunken Sir Edmund Varney after a violent argument punched a priest. the English party were requested to leave Spain.

A Visit To France

They chose to travel home via France and revisit the French court. Charles wanted to open marriage negotiations for the Princess Henrietta Maria. Charles had seen Henrietta for the first time in Paris during his outward journey to Spain, when she had been presented to him at a French court entertainment. The initial discussions regarding the marriage of Charles and Henrietta Maria were successful there were as always details and conditions that had to be agreed, however the initial discussions were successfully concluded.

The party returned home to a jubilant welcome and James concluded the matter by declaring war on Spain. Parliament would not forget that Charles Stewart had a leaning toward Rome.

Postscript

By 1624 James was growing ill his control of affairs of state and Parliament were nominal. As a result Charles had already assumed control of the kingdom in the name of the king, James passed away on the 27th of March 1625. Henrietta Maria and Charles I of England were to be married 13th June 1625.