Rule the roost

To rule the roost is to dominate, to be in control and dates in this form from the 18th century. Before this, from at least the early 1500s, the expression was rule the ‘roast’ i.e. to be in charge or in control of the kitchen, where roast meat was of paramount importance. In the 18th century it was changed to rule the roost when people began to think about cockerels in the context of being in control of the henhouse, which was a more familiar metaphor than to rule the roast.