Over the course of the Song era, the prominence of Guangzhou as a port city was eclipsed by the rise of Quanzhou, which is located about 450 miles ( 720 km ) further north along the south-eastern China coastline. Once Quanzhou supplanted Guangzhou, the interstate nature of trade between them expanded exponentially. Yet, most important for the present, whereas ascertaining conclusively whether Africans represented any quotient of the Guangzhou slaves during Song times is beyond our capacity to determine, we find that we incur no such difficulty in connection with Quanzhou.  
By far the most visible and influential of the foreign traders at Quanzhou were the Arabs, who were drawn there in great numbers by the profits to be had. The Arabs were also the most entrenched members of the Quanzhou foreign merchant community, for many of them - in direct contravention of Chinese regulations purchased dwellings or even built homesteads. Archaeological discoveries such as the unearthing of a Muslim graveyard indicate that they also died there. Inasmuch as Arab merchants came to populate Quanzhou, so did their overwhelmingly African slave-servants, which lent the Chinese city a unique deservedly ethnobinary reputation. Or, as the scholar Zhu Mu (?-after 1246) framed the situation:  
The various foreigners are all of two types, black and white, and in every case they reside in Quanzhou, which is called "the foreigners' port". Every year, they come forth by sea aboard large ships, laden with ivory, rhinoceros [horn], tortoise shell, pearls, crystals, agate, exotic fragrances and black pepper (Zhu Mu, 2003, 12.208).