Sosan, also known as Sengcan, is traditionally regarded as the Third Patriarch of Chinese Zen, or Chán. The sources converge in placing his life in the 6th to early 7th century, with approximate dates that cluster around the period from the early 500s to a death sometime in the early 600s. Although exact birth and death years are uncertain, the tradition consistently situates him in that era of Chinese Buddhist development. This temporal setting places his activity among the early generations that shaped the emerging Zen lineage.

All accounts agree that Sosan was from China, even though the precise details of his birthplace are not clearly recorded. He is associated with the formative phase of Chinese Zen communities, and his life is remembered more through lineage and teaching than through biographical detail. The emphasis on his Chinese origin and his role within an early patriarchal succession reflects how the tradition values spiritual transmission over historical exactitude. In this way, Sosan stands as a figure whose historical outline is faint, yet whose placement in time and place is firmly rooted in the shared memory of the Zen school.