Beef Steak

I'm trying to find the name of a thick steak, cut from a beef fillet, which ( depending which story you believe! ) derived its name from the noble title of a French aristocrat or from the name of the restaurant where the dish was invented by the resident chef.

Any thoughts?

Thanks for any offers :-)

Could it be 'Chateaubriand'? (I think that's the way it's spelt!)

Beef Wellington
Beef Stroganoff
White Castle?

It's probably Chateaubriand. Quoting from Joy of Cooking by Irma S. Rombauer and Marion Rombauer Becker, Bobbs-Merrill Company, Inc., 1975, p. 454,

"ABOUT FILLET OF BEEF- ...There is some dissension about classic fillet cuts for steaks. Perhaps the drawing above will help clarify the situation. Beginning and extending not quite halfway through the heavy end of an entire fillet is the head, or tenderloin butt. In the second half of the heavy end lies the Chaateaubriand section, usually cut thick enough for a double or triple portion... The cuts vary from 2 to 3 inches in thickness for Chateaubriand," etc...