The Dutch faced their first serious attacks in 1665 when Major John Scott was sent by the Governor of Barbados, Lord Willoughby, to invade the settlements in the Pomeroon. By that time, prosperous sugar plantations were already established in that area. Scott, in alliance with Caribs, seized Nova Zeelandia, and after leaving 50 men to hold it, he proceeded up the Essequibo and occupied Kyk-Over-Al with 20 men.
The occupation of Kyk-Over-Al by the English did not last long, for the Dutch Commandeur of Berbice, Matthys Bergenaar, was able to march overland with a group of soldiers and recapture it. At the same time, a French expedition arrived in the Pomeroon area to help the Dutch who were their allies. They besieged the English at the fort at Nova Zeelandia and starved the men into surrendering. The prisoners were shortly after massacred by the Arawaks who were allies of the French.
Thus, Essequibo reverted to the Dutch, and Admiral Crynssen, who had earlier captured Suriname from the English, arrived as Commandeur. He concentrated his attention on redeveloping Kyk-Over-Al and the surrounding areas. Pomeroon was not regarded as a priority.
In 1676 the Dutch established a trading post on the Pomeroon River. Ten years later, they decided to appoint a separate Commandeur to control affairs on that river while maintaining a Commandeur at Kyk-Over-Al. This caused some difficulty because the Commandeur of Kyk-Over-Al refused to render assistance to his counterpart in Pomeroon. Nevertheless, within two years, settlements sprang up and sugar cultivation was established again.
The War of the Spanish Succession of 1708-14 again brought military action to Guyana when in October 1708, three French privateers, under the command of Captain Ferry, sailed up the Essequibo and attacked settlements on both banks. The Commandeur of Kyk-Over-Al refused to send help to the settlements saying that he had to protect the Fort. At that time there were only 50 soldiers under his command. The privateers met resistance at Plantation Vryheid (Bartica) from the owner and his African slaves, but this did not last long. Only after Captain Ferry was paid a ransom of 50,000 guilders did he agree to leave with his privateers.
One year later, another group of French privateers again attacked Essequibo. Pomeroon was also attacked the same year by the French and their Carib allies. However, Commander Blake, the Post-holder, and the few soldiers under his command were able to defend the settlement after killing many of the invaders. In December 1712, Pomeroon was attacked again by a combined force of French and Spanish buccaneers, but Blake and his men were able to drive them away.
Fort nassau is found 50 miles up the berbice river.