A regency is the period of rule of a regent or regents. A regent (from the Latinregens, "[one] reigning") or regency council is a person or group of persons selected to act as head of state because the ruler is a minor, not present, or debilitated.
^Harper, Douglas. "regency". Online Etymology Dictionary. Retrieved 2014-08-18. "early 15c., "government by regents," from Medieval Latin regentia, from Latin regens (see regent). Notable instances were: France 1715-1723 (under Philip, Duke of Orleans), Britain 1811-1820 (under George, Prince of Wales, Prince Regent)..."
^Harper, Douglas. "regent". Online Etymology Dictionary. Retrieved 2014-08-18. ""one who rules during the minority or absence of a sovereign," c.1400, from the adjective (now archaic, attested in English late 14c.), from Old French regent and directly from Medieval Latin regentem (nominative regens), from Latin regens "ruler, governor," noun use of present participle of regere "to rule, direct"..."
^The Oxford English Dictionary defines the term as "A person appointed to administer a State because the Monarch is a minor, is absent or is incapacitated."