What is documented is his lineage within the Yaghlakar clan, his accession in 759, and his role in suppressing the An Lushan rebellion and adopting Manichaeism; no Uyghur, Chinese or Sogdian source ties his birth to a specific place.
What would resolve this A Uyghur, Chinese or Sogdian record naming a specific birth site, which none of the surviving sources on his reign supplies.
OpenCentral Asian history; history of ManichaeismChristopher P. Atwood, Encyclopedia of Mongolia and the Mongol Empire