The translation of a medical universitary thesis on coccyx dislocation written in Latin in 1770 by our co-author allowed us to report the state of the art in coccydynia at that time.The thesis of 20 pages, entitled « De Coccygis Luxatio » was found on Google Books. The tools for translation were a Latin grammar textbook and a Latin to French dictionary.The anatomy is accurately described with the second bone being the smallest, the third exhibiting bony excrescences at the tip and the sacrococcygeal angle more open in females. The means of union are described as ligaments and a “ligamentous” substance similar to the one “filling in the lumbar discs”. The functions of the coccyx are to give attachment to the muscle Levator Ani, to support the rectum and to seal the sacral canal in order to prevent air-damage to the medulla. Causes of coccydynia are inwards (ID) and outwards dislocation (OD). ID are caused by a difficult childbirth, OD by falls or blows and are considered more severe lesions because of the associated contusion which could lead, according to the text, to an abscess and to death. The clinical signs of displacement are considered unreliable as the same abnormalities do exist in normal subjects. The symptoms are of better value: anal weight, excruciating pain when moving the thighs or when sneezing or coughing. No mention is made of a connection with sitting (perhaps because occupational activities were mostly standing?). Treatment of OD comprises a manual reduction by pressing on the coccyx back into place and a bandage to secure the reduction. ID are treated by an internal manual reduction with the forefinger covered with oil, insertion of a paste into the anus to keep it in place, bloodlettings, enema and topics to treat the associated contusion and to prevent any collection. In both cases, rest to avoid the patient sitting at all until the dislocation has healed, narcotics, spirits, diet and the use of a perforated seat are recommended.This thesis offers an insight into the infancy of modern medicine: use of an international language, symptoms explained by anatomy, allusion to the reproducibility of signs and logical treatment.