a Roland for an Oliver an effective or appropriate retort or response; tit for tat. archaic

☞ The phrase alludes to the evenly matched single combat between Roland, the legendary nephew of Charlemagne, and Oliver, another of Charlemagne's knights (paladins). Neither man was victorious and a strong friendship subsequently developed between them. According to the French medieval epic the Chanson de Roland, Roland was in command of the rearguard of Charlemagne's army when it was ambushed at Roncesvalles (now Roncevaux) in the Pyrenees in 778; despite the urging of Oliver that he should blow his horn to summon aid, Roland refused to do so until too late, and they were slain along with the rest of the rearguard.