That is the normal time to move Bearded Iris, once the flowers have finished, the roots die off and are them replaced with new ones.

thanks owdb, I will enjoy their flowers and then try to shift them. Do you just plonk them in approximately the same angle (I've never grown Iris before)? I'm thinking of re-homing them somewhere slightly less dry than they are now but I seem to know they should be proud of the soil?

Transplant as soon as blooming is done. Some people trim the leaves into a fan shape, but dont cut too short.
Do not completely cover rhisomes. They like sun.

Also run the rhizomes, north south so the leaves do not shade them. Odd advice as all mine grow in circles so some of the leaves shade the roots anyway, naturally. They like a dry soil. The reason for trimming the leaves is to stop the plant from falling over while it makes new roots. When replanting you can remove all the old dead roots and just leave the new ones. Difference in colour is brown for old and creamy white for new.

Thanks everyone I will hope for a successful transplant