It was considered one of the principal rivers of Asia Minor (Anatolia) in classical antiquity, and is mentioned in the Iliad[1] and in Theogony.

[5] In Geographica, Strabo wrote during classical antiquity that the river had its sources on Mount Adoreus, near the town of Sangia in Phrygia, not far from the border with Galatia,[6] and flowed in a very tortuous course: first in an eastern direction, then toward the north, then in a northwesterly direction and finally to the north through Bithynia into the Euxine (Black Sea).

Pseudo-Plutarch wrote that a man named Sagaris often disdained the mysteries of the Mother of the Gods, frequently deriding her priests.

[7] Part of its course formed the boundary between Phrygia and Bithynia, which in early times was bounded on the east by the river.

In the 13th century, the valley of the Sakarya was part of the border between the Eastern Roman Empire and the home of the Söğüt tribe.