In the 17th century, the Pauquunaukit (anglicized as Pokanoket, literally, “land at the clearing” in Natick) were the leadership of the tribal groups that now make up the modern-day Wampanoag Nation. However, ethnically Pokanoket groups and their neighbors did not begin to refer to themselves as Wampanoag until after King Philip’s War, when Pokanoket identity was criminalized in Rhode Island and Massachusetts. Thus, while all Pokanoket are Wampanoag (being one tribe among several), not all Wampanoag are ethnically Pokanoket. The Pokanoket are the indigenous group in the first Thanksgiving story, although it is speculated that no meal was actually shared between the Pokanoket and English settlers, and the former did not necessarily welcome colonization.
Ousa Mequin or Yellow Feather, the Massasoit of the Pokanoket Tribe, is welcomed by John Winthrop in Plymouth on March 22, 1621. Shortly thereafter, they crafted the Wampanoag Treaty that remained in effect for the next fifty years.
Giovanni de Verrazano (pictured left) sailed into Narragansett Bay in 1524, and people appeared on the shores, most likely Pokanokets. The navigator’s recorded latitude of 41°40′ north corresponds to Mount Hope Bay, where the seat of the Pokanoket is located. Verrazano wrote of these Rhode Island natives whom he encountered: “These people are the most beautiful and have the most civil customs we have found on this voyage.”[from Wikipedia] 
“All evidence point to Pokanoket, not Wampanoag, being the name that Massasoit’s people called themselves. According to Kathleen Bragdon in Native People of Southern New England, 1500-1650, ‘Wampanoag, was an ethnonym, now used to designate the modern descendants of the Pokanokets, was probably derived from the name Wapanoos, first applied by Dutch explorers and map-makers to those Natives near Narragansett Bay . . . The term means ‘easterner’ in Delaware, and was probably not an original self-designation.’ p. 23″. [Nathaniel Philbrick, Mayflower: A Story of Courage, Community and War, 2006, p. 373]