Bogo JANG, who based his headquarters in the current Wando District, South Cholla Province, put minor groups on the sea of the southern Silla and widely traded with Tang and Japan as well as Islam merchants residing near the ports along the coast of china.
現在の全羅南道莞島に根拠地を置いた張保皐は、新羅南部の群小海上勢力を傘下に収め、唐・日本と手広く交易活動を行い、中国沿海諸港に居住するイスラーム商人とも交易を行った。