A man who filmed himself punching a toddler in the face then sent the video to the girl's grandparents demanding money has been jailed for 17 years.
Deividas Subacius, 29, hit the 18-month-old girl causing significant swelling and bruising to her right eye.
He then sent the video to the girl's grandparents by text message and demanded £130 or he would continue to harm the child.
The grandparents immediately called the police and Subacius was arrested.
Subacius, of Badgeney Road, March, admitted at Cambridge Crown Court to actual bodily harm, grievous bodily harm and blackmail, Cambridgeshire Police said.
He was jailed for 17 years on Friday.
During a physical examination doctors discovered eight healed fractures on the child including to her femur, wrist, collarbone and ribs.
Detective Constable Clemie Yaxley said: "This is the worst case of physical abuse in a child that I have had to deal with in my entire career.
"Had it not been for the grandparents acting in a protective manner the outcome would have been very different.
"I'm happy to say that the child is now being well cared for and has no significant lasting injuries as a result of this incident."