Edicts of Russian tsars (6)
I believe the answer is:
ukases
'edicts of russian tsars' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for ukases that I've seen before include "Official proclamations from Russia?" , "Ask Sue about the odd Russian tsar's edicts" , "Imperial decrees in old Russia" , "Tsarist decrees" .)