The Royal Knights "coat of arms" is of a simple design, and meaning. The official emblazon would read as so:
"Per bend Argent and Gules, a lion rampant gules, armed and langed azure and a cross fleury argent"

The lion, in classic heraldic fashion,  symbolizes bravery, valour, strength, and royalty, whilst the cross
represents an association with, and belief in Christianity.

Heraldry is a fascinating subject, and I heartily recommend that you consider a browse through some basics, to
understand some of the terminology and history.