In late 1643, in reaction to the outbreak of hostilities between colonists and Native Americans in the Lower Hudson Valley, Kiliaen van Rensselaer, patroon of Rensselaerswijck, decided to establish a fortified place to which his colonists could retreat in time of need. For this purpose he selected Beeren Island (now called Barren Island, although no longer an island, south of Coeymans, on the Hannacrois Creek), renaming it Rensselaersstein (fig. 13). Beeren Island constituted the southern border of the patroonship and, with the recent opening of the fur trade to private traders in mind, Van Rensselaer also conferred upon the island the staple right of Rensselaerswijck, thus forcing private ships to break bulk there for inspection and the payment of tolls. In this way, Van Rensselaer asserted the rights of his patroonship, but it was likely to put him on a collision course with both the West India Company and private traders. At the same time, Van Rensselaer appointed Nicolaes Coorn to be commander (wachtmeester) of Rensselaersstein. Coorn sailed from Amsterdam in September 1643 on the Wapen van Rensselaerswijck, which also carried a large amount of ammunition and equipment for the planned fortification, including two iron three-pounders, one cannon of 1310 pound, gun carriages, carriage wheels, tackle blocks, forty cannon balls of five and six pounds, cartridge paper, cylindrical brushes, cartridge sticks, a large ammunition chest, two hundred pounds of lead and shot, three hundred pounds of powder, eighteen muskets, five firelocks, two pistols, eighteen spears, sixteen broadswords, six entrenching tools, and twelve shovels and spades, for a grand total of ƒ 1904:18:8. When the Wapen van Rensselaerswijck arrived in New Amsterdam in March 1644, its military cargo did not go unnoticed. New Netherland fiscaal Cornelis van der Hoykens, tasked with defending the Company’s rights, quickly got wind of Van Rensselaer’s plans “to erect a fortress” on Beeren Island. In the opinion of Van der Hoykens, Beeren Island was outside of the limits of the patroonship and he considered Van Rensselaer’s attempt to erect a fortress there (which could command the river and thus shut off the West India Company’s Fort Orange) an attack on the prerogatives of the Company. The fiscaal’s official protest was met with a counter-protest by Coorn, who warned Van der Hoykens not “to frustrate the intended design” on Beeren Island. Both men thus having duly defended the rights of their respective masters, Coorn was allowed to ship all his equipment and personnel upriver. Although no information is available as to what the fortification may have looked like, there is no doubt that Coorn established himself on Beeren Island. A few months later, private trader Govert Loockermans sailed down the Hudson from Fort Orange in the yacht Goede Hoope. When the yacht passed Beeren Island, Nicolaes Coorn called out to Loockermans, ordering him to strike his flag. When asked for whom, Coorn replied: “For the stapleright of Rensselaerswijck.” Loockermans was not impressed: “I strike for no man except the Prince of Orange and the lords that I serve.” Coorn thereupon fired a canon, with the shot going through the mainsail and damaging some of the rigging. Loockermans cried out: “Fire, you dogs; may the Devil take you!” The second shot missed completely. The third shot hit the Prince’s flag, about a foot above the head of Loockermans who held the flag in his hand. The Goede Hoope sailed on without firing back only for the crew to make depositions in New Amsterdam later, so that Coorn could be sued for damages. Later references to Rensselaersstein indicate that the West India Company directors in Amsterdam took a dim view of what they regarded as the illegal usurpations of Rensselaerswijck. The fortification is described as “a certain house named Rensselaersstein,” which may suggest it was built as a blockhouse. An inventory dated 1652 of the papers and goods of the patroon’s house in Rensselaerswijck lists “a few stones retrieved from Rensselaersstein,” which suggest that the fortification at Beeren Island was abandoned and dismantled, probably when Nicolaes Coorn succeeded Adriaen van der Donck as schout of Rensselaerswijck and moved north to the main part of the patroonship in 1646.