who heads the monarchy?
The Queen.
Monarchy of the United Kingdom
The current monarch and head of state is Queen Elizabeth II, who ascended the throne in 1952.

who was the last ruling king of england UNANSWERABLE what is the monarchy of the united kingdom? The monarch and their immediate family undertake various official, ceremonial, diplomatic and representational duties.
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Monarchy of the United Kingdom [SEP] Introduction
The British monarch was the nominal head of the vast British Empire, which covered a quarter of the world's land area at its greatest extent in 1921.