Capture of Fort Casimir

The Capture of Fort Casimir was a confrontation between a Swedish force of 1 sloop and 20–30 armed soldiers under Johan Risingh against the Dutch controlled Fort Casimir under Sergeant Gerrit Bicker and a garrison of 10–12 men on May 31 1654, it ended with a Swedish victory and the fort was captured by Johan Risingh.

Prelude
In July 1651, Petrus Stuyvesant decided to go on a voyage to the Delaware River to construct a new fortress which would replace Fort Nassau and Fort Beversreede. He began by purchasing all the land south of Fort Christina all the way to Bombay Hook from the Native Americans. Then he chose a "reasonably suitable place about a mile from the Swedish fort Christina" in order to "build a fort named Casimier" which was furnished with "people and ammunitions of war, according to circumstances.”

Capture
During the first Anglo-Dutch war, which began in 1652, the Swedes decided to try and conquer Fort Casimir. When the Swedish commander, Johan Risingh first arrived to the Delaware River in late May 1654, he sailed a ship up to the fort and sent out a sloop with 20–30 men. Since there was no gunpowder in the fortress, the Dutch commander, Gerrit Bicker, decided to surrender the fort to the Swedes. He waited for the Swedish soldiers outside of the fortress, "in front of the gate", which was left open. Next, Bicker accompanied the Swedes without giving any orders to his men, where the Swedes easily overpowered the Dutch garrison of around 10–12 soldiers.

Aftermath
After the Swedes had conquered the fortress, it was renamed to Fort Trefaldigheten (Fort Trinity), after Trinity Sunday. Risingh also gave the newly renamed fortress a strong garrison, Which allowed the Swedes to control the Delaware River. The capture of the fortress also effectively cut the Fortress of Nassau from the sea.