Holmes's Bonfire was a raid on the Vlie estuary in the Netherlands, executed by the English Fleet during the Second Anglo-Dutch War on 19 and 20 August 1666 New Style (9 and 10 August Old Style). The attack, named after the commander of the landing force, Rear-Admiral Robert Holmes, was successful in destroying by fire a large merchant fleet of 140 ships. During the same action, the town of West-Terschelling was burnt down, which caused outrage in the Dutch Republic.
Background
After its victory in the St James's Day Fight on 4 and 5 August 1666 (Gregorian calendar, 25 and 26 July Julian Calendar), the English Fleet controlled the North Sea. The Dutch fleet, though having lost only two ships, was severely damaged and would for some weeks be unable to challenge the English fleet. The joint fleet commanders, George Monck, 1st Duke of Albemarle and Prince Rupert of the Rhine, on 7 August discussed how best to exploit this situation. The most advantageous course of action, initiating a permanent blockade of the Dutch coast and thus preventing the Dutch fleet from leaving port, was precluded by the fact that the supply situation of the English fleet was very poor, due to the structural lack of sufficient funding. It was to be expected that the English fleet would be forced to return to the home ports, even before the Dutch fleet was repaired. To accomplish anything of import during the limited time period available, a much more aggressive undertaking than a mere blockade was indicated: to attack one of the Dutch ports.
The most attractive Dutch targets were however also the most dangerous. In the south, the port of Rotterdam was too far inland and the naval ports of Flushing and Hellevoetsluis too heavily defended. More to the north, the vast wealth of the city of Amsterdam could only be reached by recklessly entering the Zuyderzee past most of the still active vessels of the Dutch fleet, lying in wait in the Texel. Because of these dangers, there would be no English attempts on these ports until Napoleonic times. But one lesser target was more exposed. The naval port of the Admiralty of Friesland, Harlingen, lies at the southern edge of the Waddenzee, the vast stretch of mudflats between the Frisian Isles and the continental coast. Harlingen's exit to the North Sea, located to the northwest, is the Vlie, the ancient estuary of the IJssel river, between the islands of Vlieland and Terschelling. The channel was often used as moorage and it was, correctly, assumed that a large number of merchant ships were at anchor here, sheltering from the English fleet and waiting to resume their voyage to the Baltic, each year the destination of thousands of Dutch vessels. In 2016, research showed that many ships in the Vlie were destined for Archangelsk, while there were also some forty to fifty westvaarders present, ships hoping to sail for France, Spain or Portugal.
The shoals, at this point even more dangerous than usual at the Dutch coast, were generally considered sufficient protection against any enemy attack. However, the English had the advantage of being aided by a Dutch captain, Laurens Heemskerck, known to the English as "Lauris van Hamskirck", who had fled from the Netherlands in 1665 on account of the cowardice he had shown during the Battle of Lowestoft and was afterwards condemned in absentia to perpetual banishment. Heemskerck in 1666 suggested executing a raid on the Vlie and later, in 1672, fought on the French side against his countrymen at the Battle of Solebay. On the 7th Heemskerck was sent out on Little Mary, a sixth-rate vessel of 12 cannon, to reconnoitre the coast together with Rupert's private yacht Fan Fan, returning the evening of the next day. A sweep along the coast by a frigate squadron during the following week brought only few prizes. When the English fleet, sailing along the Dutch coast from the south, anchored in front of the Texel on 16 August, during a council of war Heemskerck convinced Rupert and Monck that an attack was feasible as "(...) the islands of Vlie and Schelling were very ill guarded, notwithstanding there were Store-houses both for the States, and the East-India Fleet, and Riches to a good value".