Further to my previous answer:

First registration of nurses was in New Zealand with the Nurses Registration Act 1901. Britain much later with the Nurses Registration Act 1919 although midwives were covered by the Midwives Registration Act 1902.
Previous to the above acts there were various schools of nursing (Florence Nightingale, for example) but no agreement on length of training or expertise and of course, no examinations.
It was obviously some time after the acts were passed before the first registrations took place.