The length of his reign is not as clear as one would wish.

It could last from one year to the length of the leader's reign.

The length of his reign is unknown but must have lasted for a few years.

The exact length of his reign is unknown and his burial site has not yet been found.

However, this is disputed, as others claim the length of his reign was actually 64 years.

The reputed length of his reign appears unlikely for the time.

The sources also are inconsistent on the length of Ceawlin's reign.

The length of her reign usually is given as twenty-two years.

What does a year or two matter compared with the length of your eventual reign, hm-m-m-m?

There is some disagreement over the exact length of Ali's reign.