Shen ring

In ancient Egypt, a shen ring was a circle with a line tangent to it, represented in hieroglyphs as a stylised loop of a rope, bound to a stick.

What the French called a cartouche is in fact an elongated shen ring encircling a name of a pharaoh or god/goddess, thus "eternally protecting" that personage.

[1] The symbol could be stretched to contain other objects, which were then understood as being eternally protected by the shen ring.

[citation needed] In its elongated form the shen ring became the cartouche, which enclosed and protected a royal name.

[2] Outside of Egypt, a Tartessian archaeological site, Cancho Roano in southern Spain, has a shen ring-shaped altar.