King Charles III and Queen Camilla requested Kate Middleton — who spells her name Catherine — change her name ahead of her wedding to Prince William , according to a new biography.

“Charles and Camilla each had a royal monogram that consisted of interlocking C’s beneath a crown,” Christopher Andersen explained in “Kate! The Courage, Grace and Power of the Woman Who Will Be Queen.”

The author alleged Charles, 77, and Camilla, 78, were concerned a third royal cypher — a personalized monogram or emblem representing a royal family member — with a C “was overkill.”

A new royal book claims that Charles and Camilla asked Kate Middleton to change the spelling of her name in the run-up to her 2011 wedding to Prince William. WireImage

They wanted her to change her name from Catherine to Katherine.…