Thyamis

The Thyamis (Greek: Θύαμις), also known as Glykys (Γλυκύς) or Kalamas (Καλαμάς), is a river in the Epirus region of Greece. It flows into the Ionian Sea. It is 115 km (71 mi) long, and its drainage area is about 1,800 km² (690 sq mi), over 99% of which on Greek territory. The names of the Chameria region (Tsamouria in Greek), as well as the Chams, derive from the river's name.

Thyamis in ancient Greece was mentioned by Pausanias as forming the boundary between Thesprotis and Kestrine. In addition, Suda and Ptolemaeus mentioned it.

Some Renaissance scholars believed that the English River Thames owed its name to the River Thyamis, as early Celtic tribes were thought to have migrated from the Epirus region to England. While this belief influenced the modern spelling of the English river's name, it is no longer regarded as credible.