English

Noun

regnal number ‎(plural regnal numbers)

1. An ordinal number that distinguishes a monarch from others of the same name
   • 2011, Norman Davies, Vanished Kingdoms, Penguin 2012, p. 429:

     Umberto I, who had fought at Solferino, had been christened with the name of the dynasty's founder, and changed his regnal number from IV to I.

Usage notes

• Normally written as a Roman number e.g. Henry VIII for "Henry the eighth".