ご存じのとおり
As you know.
ご存じより
As per your understanding
Rather than that I knew, perhaps I should say...
That is the only thing that I know.
You ought to know.
You might already know this, but. . .
よく知ってるね
As if you did not know!
I know him
something that is familiar to someone
We know.
よく知っていた