They are the modern equivalent of the mottos that ran underneath the family coat of arms. Both perform similar functions. They’re signage, identification, calls to bravery and fortitude.
Mottos were in just about every respect medieval branding, and in many respects the process really hasn’t changed that much. It’s still a powerful and immediate signifier, a statement that defines and differentiates.
Historically, one of the key elements of chivalry was a graphic expression of the deep competitiveness of medieval aristocracy, jockeying for favor in the court and on the battlefield, as well as asserting authority over underlings and vassals. Again, the similarities to the modern principles of branding are striking.
If you examine this template of a classic coat of arms layout, the motto is an important part of the framework – and of course the shield, supporters, wreath were crest themselves the centuries old equivalent of a logo.
In fact, the entire construct supports the core power message.
Some things just never change.