At last -- an explanation for Elvis' jumpsuits.

"He was the first one to start the jumpsuits," says Elvis Presley's (search) ex-wife, Priscilla, describing the pioneer spirit that went into her husband's decision to perform in those bejeweled, one-piece outfits with the flared pantlegs and high, open collars.

"I think that was a great style for him because it allowed him movement," she says in Friday night's two-hour documentary on CBS (search), "Elvis by the Presleys." (search)

"He was free, you know, from his jacket riding up or buckling up. He felt very comfortable with that and had hundreds of jumpsuits made."

Her testimony, on jumpsuits and other subjects, has the ring of truth in this documentary -- a companion to this week's "Elvis" miniseries -- that features Priscilla and other family members recalling the Elvis they knew intimately.

"He was like a very big kid," says a cousin, Patsy Presley Geranen, attempting to explain Elvis' penchant for spontaneous recreation, such as racing golfcarts on the Graceland grounds.

"Family was really what he thrived off of," says Priscilla, who nevertheless takes pains to acknowledge that his inattention to his family was what led to her decision to divorce him in 1973.

She is surprisingly candid, as when she tells of the hurt she suffered when she found a letter to her husband from a paramour who signed the letter "Lizard Tongue."

If not a warts-and-all documentary, "Elvis by the Presleys" is at least warts-and-some.

In addition to Priscilla, 59, and Patsy, others on hand to bear witness to life with Elvis (1935-1977) are her parents, Paul and Ann Beaulieu; longtime friend Jerry Schilling; and Priscilla and Elvis' daughter, Lisa Marie, 37.

Who was Elvis? Even with the built-in biases of people who loved him and, to this day, still make their livings from his memory, this documentary comes as close as any to locating the real man beneath the famous jumpsuits.

"Elvis by the Presleys" Tonight at 8 p.m. EDT on CBS.