It is believed that the Călușari (Romanian: Căluşari, Romanian pronunciation: [k*lu**arj]; Bulgarian: Kalushari, Rusalii, Macedonian: Rusalii) are members of a secret fraternal society known as Căluş. They perform a mystical and graceful ritual dance called Căluş. As a Romanian tradition, the practice later spread to Bulgaria and North Macedonia. They have traditionally travelled to all the villages in Romania during the period that runs from three weeks after Easter until Pentecost, a festival called Rusalii in Romanian. For a period of two weeks, they danced with the fiddles in their localities.
As well as the Căluş ritual dance, the Căluş dance has also been preserved as a part of the cultural heritage of Vlachs of Bulgaria and Serbia as well as the Olt region of southern Romania. While the oldest documented music used in this dance dates back to the seventeenth century, it is likely that the ritual derived from ancient purification and fertility rituals using the symbol of the horse, which was worshipped as the embodiment of the sun. Interestingly enough, the name of the ritual comes from the Căluş, which is the wooden part of the horse's bridle. As part of the Căluş ritual, local men enacted a series of games, skits, songs and dances to the accompaniment of two violins and an accordion, accompanied by an all-male troupe of Căluşari dancers. In the past, young men used to be initiated into the magical ritual by a vataf (master) who had inherited the knowledge of descántece (magical charms) and the dance steps from his predecessor. Căluşari dancers wear a variety of colourful hats, embroidered shirts, and bell-encrusted trousers which are worn to perform a range of complex dances consisting of stamping, clicking of heels, leaping, and swinging of the legs, which are performed by a group of them.
It is said that the Căluşari were groups of dancing and chanting people who were thought to possess magical healing powers, wandering from house to house, promising good health and prosperity to the villagers.
Căluşari have been gathering on Whit Sunday since ancient times to celebrate their dancing and musical prowess. The Căluş ritual, in addition to illustrating the rich cultural diversity of Romania, has also been widely supported by folklore festivals, such as the Caracal Festival in the region of Olt, becoming a true symbol of the country.
References: https://en.wikipedia.org/wiki/C%C4%83lu%C8%99ari https://ich.unesco.org/en/RL/clu-ritual-00090