A handout photo provided to the media on Monday, July 21, 2008, shows a Liberty & Co., silver cup and cover designed by Archibald Knox

Hollywood watchers wondering why Brad Pitt and Angelina Jolie named their new son Knox may now have a clue -- an obscure designer called Archibald Knox.

Pitt started his art collection with works by Knox (1864- 1933), a U.K. Arts & Crafts maker of Celtic-influenced objects in silver and pewter for Liberty & Co., dealers said.

The actor's son was born in Nice, France, on July 12, moments before his twin sister Vivienne Marcheline. He was named Knox Leon Jolie-Pitt, the BBC reported on its Web site.

When contacted yesterday by e-mail, Pitt's office did not immediately reply to a request to say why he chose ``Knox.''

Last week, Pamela Redmond Satran, co-author of ``Cool Names for Babies,'' said that the name may have been inspired by Pitt's maternal grandfather, Hal Knox Hillhouse, who died when the actor was 11 years old, according to the Web site http://www.usmagazine.com.

``Brad got exposed to Archibald Knox in the early 1990s when he was in London filming ``Interview with a Vampire,''' said Daniel Morris, co-founder of the New York dealers, Historical Design Inc., in a telephone interview. ``He bought most of the top things in our first Knox exhibition in 1995. I think it's very possible that he named his son after Knox.''

Pitt lent a Knox silver cup and cover to the ``Liberty Style'' exhibition in Japan in 1999-2000, according to the Archibald Knox Society's Web site.

``Not many people are aware of the extent Brad Pitt has been collecting Knox,'' said Liam O'Neill, chairman of the society, in a phone interview.