The Dorset Palaeo-Inuit emerged at some point around 2,800 years ago (ca. 800 to 500 BCE). They persisted until 600 to 700 years ago (ca. 1300 to 1400 CE). Archaeologists generally separate this roughly 2,000-year period into three periods or traditions. These periods are called the Early Dorset (ca. 800 BCE to 1 CE), Middle Dorset (ca. 1 to 500 CE) and Late Dorset (ca. 500 to 1300-1400 CE). The timing and causes of their disappearance are still debated. However, it occurred only a few centuries after the arrival of the early Inuit (Thule). Early Inuit were culturally and genetically distinct from the Dorset (see also Geographical Distribution of the Dorset Culture).
While there is significant debate regarding the validity of the Early-Middle-Late periods, there are a number of notable changes that should be considered. In any case, the Dorset period marks a significant shift from the lifeways of their Pre-Dorset ancestors.