Other Reasons
Prior to 1788, regents occasionally ruled the United Kingdom and England prior to the establishment of the UK. However, this had never happened because of an incapacitated monarch. In 1714 for one, the Lord Chief Justice ruled as the nation waited for George I to take the throne. It is more common for regents to serve during the war when the king was either absent or simply a minor.
Other Reasons
The Regency Act
The Regency Act was passed in 1937. It happened because King George VI was not feeling well. There had been a very real possibility that Elizabeth was going to have to serve as the regent in his place. This was how they outlined the process of choosing a regent. It is interesting to hear that it was not a measure to be taken very strictly if the monarch is sick or old. For one thing, a temporary regent was going to be appointed if the leader thought that they could not approve legislation in good conscience.
The Regency Act
