According to an ancient hellenic myth, Callisto was the daughter of Lykaonas, the king of Arcadia. As a young girl, she vowed to the goddess Artemis to be forever faithful and devoted to her. She was to remain a virgin forever in order to serve and accompany her while hunting animals in the forest. However, one day, Zeus, the father of the gods fell in love with Callisto and forced her to sleep with him. Callisto gave birth to a son whom she named Arcadian. Zeus knew that if Hera, his wife, learned of his disloyalty she would be angry with Callisto, so in order to protect her he transformed her into a brown bear. Callisto, as a bear, roamed around the forest looking for her son, Arcadian. After years of searching she found Arcadian who was now a grown man. She finally ran into him and happy as she was she stood on her back legs and tried to embrace him. Arcadian however did not recognize her and thought he was being attacked, so he drew his sword trying to defend himself. Zeus, watching everything, as usual, felt sorry for them and in order to prevent this tragedy he transformed them into constellations (Ursa major and Ursa minor) and placed them near to him in the sky. Hera, who was still furious, asked the Ocean, the river that surrounds the earth, not to permit them to wash themselves in his waters; therefore these two constellations are always seen high in the night sky. Moreover in order to protect them from Hera's jealousy he placed another star near to them, called Arcturos, which means the guardian of Arctos, the bear. It protects and accompanies them for eternity.

ARCTUROS was founded in 1992 in order to put an end in the phenomenon of the 'dancing bear' which was at the time a common sight around Greece. Since then ARCTUROS has been actively working for the conservation of large carnivores both in Greece and around the Balkans. Through applied research it gathers information that allows dynamic intervention in cases where important habitats are threatened or destroyed by large technical works such as roads, dams, quarries and so on. At the same time it carries out Special Environmental Studies in areas of high ecological significance. Over the last 15 years ARCTUROS has developed initiatives based on legislative provisions previously not put into action, which improved existing regulations or the establishment of new provisions.