The part of the sentence "king exercised power" is correct and usable in written English.
It can be used to indicate the power or authority that a ruler has. For example, "The king exercised power through his decrees of law."
Thus ended the last attempt of a medieval king to exercise arbitrary power.
Power is power, exercised similarly by both left and right.
In addition to their administration by the French-led Wallis and Futuna government (including a locally elected legislature), the islands are ruled by a king who exercises limited powers.
There is also a what-if fascination to seeing how a future king might exercise long-dormant powers, invoke army support and leave the country bitterly divided.
However, the king had to exercise this power with care and after consulting with his advisers.
From the moment of their coronation, the heirs were regarded as junior kings (rex iunior), but they exercised little power and historically were not included in the numbering of monarchs if they predeceased their fathers.
There are monarchists who are arguing for a full-scale return to the old regime and the party-less Panchayat system, in which the king exercised absolute power through village, district and national councils.
More often allied with the king than not, they exercised regalian powers of justice, command, and constraint; it was typically they who undertook to defend local settlements and churches from the ravages of Magyars invading from the east, of Muslims on Mediterranean coasts, and of Vikings from northern waters.
Outside his Cumbrian principality and the southern fringe of Scotland-proper, David exercised little power in the 1120s, and in the words of Richard Oram, was "king of Scots in little more than name".
Clarke exercised that power responsibly.
