Rheology (ρεολογία) is a branch of mechanics that studies those properties of materials which determine their response to mechanical force. The word rheology was coined in the 1920’s to represent the science of the deformation and flow of matter. Its origin goes back to the 6th century B.C. and to the Greek philosopher Herakleitus, who observed that “Τα πάντα ρει, πάντα χωρεί και ουδέν μένει (Ta panta rhei, panta hwrei, kai ouden menei)”.

The Hellenic Society of Rheology (HSR)
HSR was officially formed on June 16th, 1996, in Athens, Greece, recognised by the Greek judicial authorities having the necessary core of the first 20 founding members. Thus came into fruition the original attempts by the late Professor Tasos Papanastasiou to organize the Greek Rheological community and the many scientists and engineers who practice rheology in their professional careers.

The establishement of HSR was followed by the 1st meeting of the Society in Nicosia, Cyprus, in July 1996, where the 1st Executive (President: E. Mitsoulis) was elected and the Constitution was ratified.

The 2nd meeting of the Society was held in Heraklion, Crete, in August 31-September 2, 1998, where a 2nd Executive was elected for the period 1998-2000. The 3rd meeting of the Society was held in Cambridge, in August 25 2000. The last (8th) meeting was held at Limmasol (Cyprus) on July 13, 2017, where the current Executive was elected for the period 2017-2019.

The HSR has organized nine Conferences: in Nicosia (1996), Heraklion (1998), Patras (2001), Vouliagmeni (2004), Rhodes (2007), Athens (2011), Heraklion (2014) and Limmasol (2017). The 9th HSR Conference, honoring Professor Gary L. Leal for his contributions to Rheology and Fluid Mechanics, took place, from 24 to 27 of June, 2019, in Samos, Greece.

The next 10th HSR Conference will take place from June 29th – July 2nd, 2022 in Skiathos, Greece.

In July 2023, HSR co-organizes and hosts the 19th International Congress on Rheology (ICR), in Athens, Greece.

In April 2006, HSR organized the 3rd Annual European Rheology Conference on behalf of the European Society of Rheology (ESR), in Hersonissos, Crete.

Rheology enters in some form into almost every study of material properties. Many physicists, chemists, engineers, biologists and mathematicians find a common meeting ground in The Society’s meetings and publications. It is a small society compared to many others, membership currently being about 40. The membership represents a wide spectrum of individuals from academic, industrial, and governmental institutions whose activities include both phenomenological and molecular theories, instrumentation, the study of many types of materials such as polymers, metals, petroleum products, rubber, paint, printing ink, ceramics and glass, foods, biological materials, floor preparations and cosmetics, and a wide range of practical applications.

The Hellenic Society of Rheology is one of the fifteen founding members of the European Society of Rheology. By virtue of this affiliation, all Members of The Society receive the ESR’s Newsletter. The Society is also a member of the International Committee on Rheology, which organizes the International Congress on Rheology.