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.
(..) of this alliance? With all my heart, sire. Then why do you spread tales... of an heir to the throne left by Queen Enid? 'Tis common knowledge, sire. The queen on her deathbed spoke of a son... sent off to Italy with the pommel stone... of the sword Requiter (..)1958 The Vikings