Unknown to somebody - Idioms by The Free Dictionary
unknown to somebody
unknown to (one)
With someone being unaware (of something). Unknown to Jacobson, the other two partners had drawn up the deal in such a way that they would have full control of the company in two years' time. My wife invited her entire family to come stay with us for Christmas—unknown to me.
unknown to somebody without the person mentioned being aware of it: Unknown to me, he had already signed the agreement.
References in periodicals archive
Now she is setting out to complete phase two of her ambition: to top the best seller list and the way things are going she looks set to go from unknown to somebody