A man who attempted to murder his 97-year-old father in a "savage attack" has been detained for 14 years.
Janek Martens was severely injured in the attack at home in St Annes, near Blackpool, Lancashire, in March.
Stefan Martens, 58, of St Annes, denied intending to kill him but was found guilty at Preston Crown Court.
He was given a hospital order and will start his sentence in a specialist centre receiving treatment under the Mental Health Act.
He had admitted a lesser charge of wounding with intent.
Det Sgt Nick Denman of Lancashire Constabulary said: "This was a tragic case where an elderly man has been subjected to a savage attack by his own son - to try to comprehend and come to terms with that must be extremely difficult for both Janek and the wider family.
"Hopefully the conclusion of this sad case will at least offer the opportunity to the Martens family to try to move on with their lives."
Janek Martens has since been released from hospital and is now in a care home.