Hapsburg Jaw: Of the numerous characteristics identified within the dynasty of Habsburg it is the genetically passed on over-grown jaw or “mandibular prognathism” that gets the most responsiveness. It is very plainly noticeable in most of the growing accepted portraits of those family members since the Renaissance and after as well as also being seen on coins of that period. What is seen from the portraits that survived is the deformity advanced and enlarged with the age of the individuals. Often it was so severe as to affect eating or talking and often associated to the lacking of mental sharpness, but the problem never interfered with hereditary succession.
Well assisted by a competent bureaucracy, the Habsburgs tolerated despite growing inattentiveness to responsibility and only vanished in Spain due to the king’s failure to create an heir.
There’s no disagreement that this genetic defect came into the family with Cymburga of Masowia in the early 15th century when she wedded Duke Ernst of Inner Austria. The nobility in Europe had by then already exhaustively intermarried and so the factual sources of such genetic aberrations is too often hidden in mystery and complex ancestry. Who, which pairing, or which ancestors brought this defect is beyond knowing.