Aberdeen have confirmed the appointment of former Motherwell boss Craig Brown as manager on a two-and-a-half year contract.
The pair will be officially unveiled on Monday, with caretaker bosses Neil Cooper and Neil Simpson remaining in charge for Saturday's SPL clash against Hearts at Tynecastle.
Aberdeen chairman Stewart Milne said: "I don't think it's any secret Craig and Archie were our first choice and it's fantastic that they've agreed to come on board."
While the formalities of the deal were completed tonight, agreement was reached in principle last night before Brown and Knox stunned Motherwell with their resignations following a dramatic U-turn.
Motherwell have reported Aberdeen to the SPL over an alleged illegal approach but the Dons denied wrongdoing.
Milne said: "An agent contacted the club last week with regard to Craig and Archie and we indicated we would be keen to talk.
"Craig subsequently informed Motherwell that Aberdeen were interested in speaking to him and the Fir Park club raised no objection.
"Motherwell's subsequent statement on Wednesday referred to the fact there had been discussions between the parties without any suggestion of criticism of ourselves and it was therefore a surprise to us and Craig to learn of the accusations of inappropriate conduct."
