Laid down the law (5)
I believe the answer is:
ruled
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">laid down the law</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for ruled that I've seen before include "Governed or commanded" , "Governed - with lines" , "Reigned - lined - decided" , "Exercised control over" , "Reigned or ordered" .)