It was mentioned only once in the 2nd century by the orator and medicinal writer Aelius Aristides in his "Hieroi Logoi" (Sacred Tales) (III.1), one of the key sources for the knowledge on the science of healing as it was understood at that time.

During the excavations conducted in the forest to the west of Allianoi, a vessel of the type known as Yortan (dating from the Early Bronze Age II) was found.

Because of the presence of hot springs, it is thought that there must have been a thermal bath complex already in the Hellenistic period, but probably at a smaller scale than the later Roman site.

During the Roman Imperial Period and especially as of the 2nd century AD, consistent with the emergence of a multitude of urban centers in Anatolia and also with the construction of the famous Asklepion of nearby Pergamon, the number of public works built in Allianoi also increased.

Besides the thermal baths, the bridges, the streets, the insulae, the Connection Building, propylon and the nympheum were all planned and built during this period.

In the beginning of the 20th century, the sub-governor of the region did start an effort to put the spa complex back to use and the big pool section has been partially refurbished.

These recent elements were removed in 2003 by the excavation team and the major parts of the Bath Complex beneath them started to come to light.

[1] The Allianoi bath complex lies within the proposed reservoir area, meaning it would be covered in water should the dam project go through.