the office of or period of government by a regent

the boy being a minor, there would have to be a regency

relating to or denoting British architecture, clothing, and furniture of the Regency or, more widely, of the late 18th and early 19th centuries. Regency style was contemporary with the Empire style and shares many of its features: elaborate and ornate, it is generally neoclassical, with a generous borrowing of Greek and Egyptian motifs