I know that there were lawyers during the Classical era, although both the lawyers and judges were highly politicized at least in Rome. I would imagine that keeping track of every ancient precedent and legal clause would be considered too tedious for a king/duke, and too important to be handed over to a general advisor or diplomat. If such lawyers existed, were they lowborn or noble?
There were indeed lawyers, as attested to by Ælfric's Colloquy. I wrote about them here.