I answered their questions 'to the best of my knowledge'. [=I gave the best answers I could based on what I knew, but I might have answered differently if I had known something else]
No one arrived late 'to my knowledge'. [=I am not aware that anyone arrived late, but it is possible that someone arrived late and I don't know about it]
They went on vacation, 'safe in the knowledge' that the farm would be well cared for while they were away.
(..) - What was that? - An accident, but nobody was hurt. Tom, will you give this letter to Michael. Please? If I accepted that, a court could prove I have knowledge of his whereabouts. He'll get in touch with you. I let my cab go, so can I call another one, please? Come on. Sorry. - Hello? (..)1972 The Godfather