Dr. Johnson’s Dictionary

To rule the ROAST. To govern; to manage; to preside. It
was perhaps originally roist, which signified a tumult, to
direct the populace.
The new-made duke, that rules the roast.  Shakesp.
Where champions ruleth the rost,
There dailie disorder is most. Tusser’s Husbandry.
Alma slap-dash, is all again
In ev’ry sinew, nerve, and vein;
Runs here and there, like Hamlet’s ghost,
While every where she rules the roast. Prior.