In 1623 Buckingham, now Lord Admiral and effective Foreign Minister, accompanied Charles I, then Prince of Wales, to Spain for marriage negotiations regarding the Infanta Maria.
 The negotiations had long been stuck, but it is believed that Buckingham's crassness was key to the total collapse of agreement, and they returned in a black mood.
 The Spanish ambassador asked Parliament to have Buckingham executed for his behaviour in Madrid, but Buckingham gained popularity by calling for war with Spain on his return.

He headed further marriage negotiations, but when, in December 1624, the betrothal to Henrietta Maria of France was announced, the choice of a Catholic was widely condemned.
 Buckingham, whose popularity had suffered a further setback, took a decision to help the rebellious Huguenot Admiral Benjamin, Duke of Soubise.
 An ardent Protestant, Buckingham ordered Sir John Pennington to help; but the Navy only succeeded in attacking Richelieu's enemies, defeating his objects in August 1625 and losing La Rochelle.
Similarly he was blamed for the failure of the military expedition under the command of Ernst von Mansfeld, a famous German mercenary general, sent to the continent to recover the Electorate of the Palatinate (1625), which had belonged to Frederick V, Elector Palatine, son-in-law of King James I of England.
However, when the Duke of York became King Charles I, Buckingham was the only man to maintain his position from the court of James
These failures provoked the Commons to refuse further levies of taxation to fund Buckingham's extravagant adventures, while at the same time the duke was accused of being enraptured by intrigues; of dealing a blow to the international Catholic conspiracy.
 Yet even before they set sail the food was consumed awaiting the Board of Ordnance to deliver the cannonry and musket balls.
 On this occasion the Lord Admiral was not in command.
 The experienced admirals were unavailable, so it fell to the newly created Viscount Wimbledon to lead the expedition with one eye on history; to repeat the actions of Sir Francis Drake by seizing the main Spanish port at Cádiz and burning the fleet in its harbour.

Although this plan was tactically sound – landing further up the coast and marching the militia army on the city – the troops were badly-equipped, ill-disciplined and poorly-trained.
Coming upon a warehouse filled with wine, they simply got drunk, and the attack was called off.
 The English army briefly occupied a small port further down the coast before re-boarding its ships.
Pennington's curse was a lack of money, but public opinion blamed Buckingham for another disaster.
 The King too was hurting; England was heading towards war with France.

This was followed by Buckingham leading the Army and the Navy to sea to intercept an anticipated Spanish silver fleet from its American territories.
 However the Spanish were forewarned by their intelligence and easily avoided the planned ambush.
With supplies running out and men sick and dying from starvation and disease, the English limped home in embarrassment.

Buckingham then negotiated with the French Chief Minister, Cardinal Richelieu, for English ships to aid Richelieu in his fight against the French Protestant Huguenots, in return for French aid against the Spanish occupying the Palatinate.
 Seven English warships participated in operations against La Rochelle and in the Siege of Saint-Martin-de-Ré, but Parliament was disgusted and horrified at the thought of English Protestants fighting French Protestants.
 The plan only fuelled their fears of crypto-Catholicism at court.
 Buckingham fought bravely throughout, but Richelieu's ships blocked the narrow channel, and he had to accept defeat by withdrawal.
 Believing that the failure of his enterprise was the result of treachery, he formulated an alliance among the churchman's many enemies, a policy that included support for the very Huguenots whom he had recently attacked.

In 1627, Buckingham led another expeditionary force.
Shortly before departure Buckingham had authorized a new dry dock at
In 1623 Buckingham, now Lord Admiral and effective Foreign Minister, accompanied Charles I, then Prince of Wales, to Spain for marriage negotiations regarding the Infanta Maria.  The negotiations had long been stuck, but it is believed that Buckingham's crassness was key to the total collapse of agreement, and they returned in a black mood.  The Spanish ambassador asked Parliament to have Buckingham executed for his behaviour in Madrid, but Buckingham gained popularity by calling for war with Spain on his return.
He headed further marriage negotiations, but when, in December 1624, the betrothal to Henrietta Maria of France was announced, the choice of a Catholic was widely condemned.  Buckingham, whose popularity had suffered a further setback, took a decision to help the rebellious Huguenot Admiral Benjamin, Duke of Soubise.  An ardent Protestant, Buckingham ordered Sir John Pennington to help; but the Navy only succeeded in attacking Richelieu's enemies, defeating his objects in August 1625 and losing La Rochelle. Similarly he was blamed for the failure of the military expedition under the command of Ernst von Mansfeld, a famous German mercenary general, sent to the continent to recover the Electorate of the Palatinate (1625), which had belonged to Frederick V, Elector Palatine, son-in-law of King James I of England. However, when the Duke of York became King Charles I, Buckingham was the only man to maintain his position from the court of James
These failures provoked the Commons to refuse further levies of taxation to fund Buckingham's extravagant adventures, while at the same time the duke was accused of being enraptured by intrigues; of dealing a blow to the international Catholic conspiracy.  Yet even before they set sail the food was consumed awaiting the Board of Ordnance to deliver the cannonry and musket balls.  On this occasion the Lord Admiral was not in command.  The experienced admirals were unavailable, so it fell to the newly created Viscount Wimbledon to lead the expedition with one eye on history; to repeat the actions of Sir Francis Drake by seizing the main Spanish port at Cádiz and burning the fleet in its harbour.
Although this plan was tactically sound – landing further up the coast and marching the militia army on the city – the troops were badly-equipped, ill-disciplined and poorly-trained. Coming upon a warehouse filled with wine, they simply got drunk, and the attack was called off.  The English army briefly occupied a small port further down the coast before re-boarding its ships. Pennington's curse was a lack of money, but public opinion blamed Buckingham for another disaster.  The King too was hurting; England was heading towards war with France.
This was followed by Buckingham leading the Army and the Navy to sea to intercept an anticipated Spanish silver fleet from its American territories.  However the Spanish were forewarned by their intelligence and easily avoided the planned ambush. With supplies running out and men sick and dying from starvation and disease, the English limped home in embarrassment.
Buckingham then negotiated with the French Chief Minister, Cardinal Richelieu, for English ships to aid Richelieu in his fight against the French Protestant Huguenots, in return for French aid against the Spanish occupying the Palatinate.  Seven English warships participated in operations against La Rochelle and in the Siege of Saint-Martin-de-Ré, but Parliament was disgusted and horrified at the thought of English Protestants fighting French Protestants.  The plan only fuelled their fears of crypto-Catholicism at court.  Buckingham fought bravely throughout, but Richelieu's ships blocked the narrow channel, and he had to accept defeat by withdrawal.  Believing that the failure of his enterprise was the result of treachery, he formulated an alliance among the churchman's many enemies, a policy that included support for the very Huguenots whom he had recently attacked.
In 1627, Buckingham led another expeditionary force. Shortly before departure Buckingham had authorized a new dry dock at 
George Villiers, 1st Duke of Buckingham