Oghulchak Arslan Khan was the third and lastKarakhanid Khagan to follow the nativeTurkic religion ofTengrism. He was aBughraKhagan during his elder brotherBazir Arslan's rule in the west. He was titledArslan Khagan after his ascension to the throne.

He may have clashed with theSamanid emirIsmail inTalas, 893.^[1] After withdrawing toKashgar, he welcomed the influx of Muslim traders to the city, even allowing them to build a mosque in the town ofArtux just outside Kashgar. Growing Muslim presence led to the secret conversion of his nephew,Satuq Bughra Khan. When Oghulchak heard that Satuq had become aMuslim, he demanded that Satuq build a Tengriist temple to show that he hadn't converted. Nasr, the Persian merchant who converted Satuq to Islam, advised him that he should pretend to build a temple but with the intention of building a mosque in his heart.^[2] The khagan, after seeing Satuq starting to build the temple, stopped him, believing that he had not converted. Afterwards, Satuq obtained afatwa which permitted him in effect to kill his uncle, after which he conquered Kashgar.

• 942 deaths
• 9th-century monarchs in Asia
• Tengrist monarchs

• Articles with short description
• Short description is different from Wikidata
• Year of birth missing