Songzhou or Song Prefecture (宋州) was a zhou (prefecture) in imperial China centering on modern Shangqiu, Henan, China. It existed (intermittently) from 596 to 1006.
The Song dynasty was named after this prefecture because its founder Emperor Taizu of Song had stationed in Songzhou for many years.
Sòng Prefecture Wikipedia
The administrative region of Songzhou in the Tang dynasty is in the border area of modern eastern Henan, northern Anhui and southwestern Shandong. It probably includes parts of modern:Under the administration of Shangqiu, Henan:
Shangqiu: Liangyuan District and Suiyang District
Under the administration of Heze, Shandong:
Under the administration of Suzhou, Anhui: