Erté was the working name of Russian-born French artist Romain Tyrtov. His initials were R.T., so he used the pronunciation of the letters as his pseudonym.
Erté is perhaps most famous for his elegant fashion designs which capture the Art Deco period in which he worked. His delicate figures and sophisticated, glamorous designs are instantly recognizable, and his ideas and art still influence fashion into the 21st century. His costumes, program designs and sets were featured in the Ziegfeld Follies of 1923 [and] many productions of the Folies Bergère...The best online collection of his work that I've been able to find tonight is at Purple Dragon's Erte page.
Image above via Ordinary Finds. Click to enlarge.