In 1664, a year before the Second Anglo-Dutch War began, Robert Holmes had captured several Dutch West India Company trading posts and ships on the West African coast, where companies from the two nations were rivals in the slave trade.
Although Johan de Witt wanted to avoid an all-out war with England, he considered that this provocation must be responded to, and proposed to the States General that De Ruyter's squadron in the Mediterranean should be sent to West Africa to retake the West India Company's forts there.
De Ruyter received his instructions at Málaga on 1 September 1664 and, by early the next month, all the Dutch West African posts had been recaptured and the squadron was ready to cross the Atlantic to attack English shipping in the West Indies and at the Newfoundland fisheries in reprisal.

De Ruyter's activities in the American waters had less satisfactory results than those off West Africa.
Arriving off Barbados in the Caribbean at the end of April 1665 aboard his flagship Spiegel ("Mirror"), he led his fleet of thirteen vessels into Carlisle Bay, exchanging fire with the English batteries and destroying many of the vessels anchored there.
Unable to silence the English guns and having sustained significant casualties and considerable damage to his vessels, he retired to French Martinique for repairs.

Sailing north from Martinique, De Ruyter captured several English vessels and delivered supplies to the Dutch colony at Sint Eustatius.
In view of the damage that his ships had sustained at Barbados, he decided against an assault on New York, formerly New Amsterdam which would have been necessary, had the Dutch wished to retake their former New Netherland colony.
De Ruyter then proceeded to Newfoundland, capturing some English merchant ships and temporarily taking the town of St. John's before returning to Europe, travelling around the north of Scotland as a precaution.

In December 1664, the English fleet attacked the Dutch Smyrna fleet.
Though the attack failed, the Dutch in January 1665 allowed their ships to open fire on English warships when threatened.
War was declared by the Dutch on 4 March 1665, following two further English attacks on Dutch convoys, one off Cadiz and another in the English Channel.
The Dutch fleet was confident of victory, but it contained a significant proportion of older or weak ships.
In the first year of the Second Anglo-Dutch War, at the Battle of Lowestoft on 13 June 1665, the Dutch suffered the worst defeat in the history the Dutch Republic's navy.
At least sixteen ships lost, and one-third of its personnel captured or killed; Van Wassenaer was among the dead.

On his return to the republic, De Ruyter learned that Van Wassenaer had been killed at Lowestoft.
Cornelis Tromp had been put in temporary command of the confederate fleet after the battle, but was not acceptable to the regime of Johan de Witt because of his support for the Orangist cause.
De Ruyter was politically neutral, but on friendly terms with Johan de Witt and his associates.
His successes in distant waters, which ensured he was not involved in the battle of Lowestoft and tainted by that defeat, made him the obvious candidate to succeed Van Wassenaer as commander of the Dutch fleet, which he did on 11 August 1665.
He was therefore made lieutenant-admiral, a rank he then shared with six others in the Dutch admiralties.

In the second year of the war, 1666, De Ruyter won the hard-fought Four Days' Battle of 1 to 4 June 1666.
The division of the English fleet gave the Dutch the advantage of numbers on the first and second days of fighting.
An English attack on the anchored Dutch fleet on the first day was resisted and, after two days fighting, the English fleet retreated towards the Thames.
However, the English fleet was reinforced by a squadron of undamaged ships on the third evening and fought strongly on the fourth day, so that Tromp seemed near to defeat in the afternoon, until De Ruyter decided the battle with a surprise all-out attack that demoralised his opponents into retreat.

However, the English fleet was not
In 1664, a year before the Second Anglo-Dutch War began, Robert Holmes had captured several Dutch West India Company trading posts and ships on the West African coast, where companies from the two nations were rivals in the slave trade. Although Johan de Witt wanted to avoid an all-out war with England, he considered that this provocation must be responded to, and proposed to the States General that De Ruyter's squadron in the Mediterranean should be sent to West Africa to retake the West India Company's forts there. De Ruyter received his instructions at Málaga on 1 September 1664 and, by early the next month, all the Dutch West African posts had been recaptured and the squadron was ready to cross the Atlantic to attack English shipping in the West Indies and at the Newfoundland fisheries in reprisal.
De Ruyter's activities in the American waters had less satisfactory results than those off West Africa. Arriving off Barbados in the Caribbean at the end of April 1665 aboard his flagship Spiegel ("Mirror"), he led his fleet of thirteen vessels into Carlisle Bay, exchanging fire with the English batteries and destroying many of the vessels anchored there. Unable to silence the English guns and having sustained significant casualties and considerable damage to his vessels, he retired to French Martinique for repairs.
Sailing north from Martinique, De Ruyter captured several English vessels and delivered supplies to the Dutch colony at Sint Eustatius. In view of the damage that his ships had sustained at Barbados, he decided against an assault on New York, formerly New Amsterdam which would have been necessary, had the Dutch wished to retake their former New Netherland colony. De Ruyter then proceeded to Newfoundland, capturing some English merchant ships and temporarily taking the town of St. John's before returning to Europe, travelling around the north of Scotland as a precaution.
In December 1664, the English fleet attacked the Dutch Smyrna fleet. Though the attack failed, the Dutch in January 1665 allowed their ships to open fire on English warships when threatened. War was declared by the Dutch on 4 March 1665, following two further English attacks on Dutch convoys, one off Cadiz and another in the English Channel. The Dutch fleet was confident of victory, but it contained a significant proportion of older or weak ships. In the first year of the Second Anglo-Dutch War, at the Battle of Lowestoft on 13 June 1665, the Dutch suffered the worst defeat in the history the Dutch Republic's navy. At least sixteen ships lost, and one-third of its personnel captured or killed; Van Wassenaer was among the dead.
On his return to the republic, De Ruyter learned that Van Wassenaer had been killed at Lowestoft. Cornelis Tromp had been put in temporary command of the confederate fleet after the battle, but was not acceptable to the regime of Johan de Witt because of his support for the Orangist cause. De Ruyter was politically neutral, but on friendly terms with Johan de Witt and his associates. His successes in distant waters, which ensured he was not involved in the battle of Lowestoft and tainted by that defeat, made him the obvious candidate to succeed Van Wassenaer as commander of the Dutch fleet, which he did on 11 August 1665. He was therefore made lieutenant-admiral, a rank he then shared with six others in the Dutch admiralties.
In the second year of the war, 1666, De Ruyter won the hard-fought Four Days' Battle of 1 to 4 June 1666. The division of the English fleet gave the Dutch the advantage of numbers on the first and second days of fighting. An English attack on the anchored Dutch fleet on the first day was resisted and, after two days fighting, the English fleet retreated towards the Thames. However, the English fleet was reinforced by a squadron of undamaged ships on the third evening and fought strongly on the fourth day, so that Tromp seemed near to defeat in the afternoon, until De Ruyter decided the battle with a surprise all-out attack that demoralised his opponents into retreat.
However, the English fleet was not
Michiel de Ruyter