Poggatacut also known as Youghco or Poggatticut, was sachem of the Manhasset Indian people of Shelter Island, New York and elder brother to Montaukett Sachem Wyandanch. Sachem Poggatacut and his wife Aswaw granted possession to Lion Gardiner for Gardiners Island in 1639. It was conveyed when they deeded Manchonat, an Island between the north and south fork in exchange for goods and alliance. By 1644 he had united the Corchaug, Shinnecock, Manhassets and Montaukett before retreating as Grand Sachem to his redoubt on Shelter Island, relinquishing control over the tribes to his younger brother, sachem Wyandanch. As “Sachem of Paumanacke", as Long Island was called, he was empowered to make treaties for the Montauketts.

Wyandanch (c. 1571 – 1659 was a sachem of the Montaukett Indians in the mid-17th century on eastern Long Island. Initially he was a minor chief among the Montaukett, but due to his skillful manipulation of various alliances and his accommodating stance towards the European colonists who gave him substantial military and economic support, he eventually became an influential "alliance chief" (a sachem who was responsible for maintaining friendly relations between his tribe and the settlers).