From the UK Telegraph:
Inbreeding caused demise of the Spanish Habsburg dynasty, new study reveals
The study found that nine out of 11 marriages over the 200 years were between first cousins or uncles and nieces, producing a small gene pool that made rare recessive genetic illnesses more prevalent.
Only half of the babies born to the dynasty during the period studied lived to see their first birthday, compared with about 80 per cent of children in Spanish villages at the time.
Also, we have found a few pictures of the last remaining members of the Hapsburg family.