The Pequot War, the first major conflict between Native Americans and Europeans in northeastern North America, began in September 1636, lasted eleven months, and involved thousands of Native and English people in several major battles in present-day Connecticut. In the early months, most fighting occurred around Saybrook Fort during the Siege and Battle of Saybrook Fort from September 1636 to March 1637, when Lieutenant Lion Gardiner defended the fort against repeated Pequot attacks through the fall and winter and more than half of the garrison became casualties. In early March 1637, the siege ended when the English-allied Narragansett attacked Pequot country from the east and reinforcements from Massachusetts Bay under Captain John Underhill arrived. For the rest of the war, Saybrook Fort served as the main gathering place for English forces before campaigns against the Pequot at Mistick and Quinnipiac, and after the war it remained in use until fire destroyed it in 1647. Built to control the Connecticut River Valley, Saybrook Fort was the first English military installation in Connecticut and was intended as a safe haven for Saybrook proprietors who opposed the King. Designed by John Winthrop, Jr. and Lieutenant Lion Gardiner, it was an important regional fortification, though its exact location and design were later lost. Evidence indicates it was smaller than originally planned but included palisade walls, a gate, at least one warehouse, and two cannons called sakers, and Gardiner likely used the Dutch Old Netherland style with a square plan and opposing bastions suited to a garrison of twenty soldiers commanding the river and land approaches from Saybrook Neck. Historical and archaeological research conducted in 2012 and 2013 suggests the fort stood on the highest ground in the northeastern corner of Saybrook Point near North Cove and Gees Pond, with a warehouse, wharf, and fenced garden nearby. Artifacts including musket balls, gun parts, and early buttons indicate continued fighting on nearby sloping ground during the siege, though no visible remains of the fort survive today.