A Florida transsexual was granted primary custody of his two children Friday after a judge delivered a sweeping 800-page written decision that answered, for now, the question of just what makes a man under the law.

Linda Kantaras

According to the decision, Michael Kantaras, who had breast removal surgery and hormone therapy to swap genders, is indeed a man and therefore his marriage, and custody claim, were valid in Florida, which does not recognize same-sex marriages. 

"Chromosomes are only one factor in the determination of sex and they do not overrule gender or self-identity which is the true test or identifying mark of sex," wrote Pasco County Judge Gerard O'Brien. "Michael has always, for a lifetime, had a self-identity as a male."

O'Brien's ruling stands to impact much more than one family's insular custody battle.  "It's a complete victory for Michael Kantaras, and it's a victory for all transsexuals," said Kantaras' attorney, Collin Vause. 

Under the ruling, Linda Kantaras, 34, will have visitation rights to Matthew, 13, and Irina, 11, every other weekend. Her lawyer, Claudia Wheeler, had argued that Michael Kantaras, who still had female-like genitilia, was not legally a man and that their marriage was null and void. A woman at Wheeler's office said the lawyer was unavailable for comment Friday.

Judge O'Brien's written decision was more than a year in the making. Lawyers delivered closing arguments more than a year ago after a bitter courtroom battle that focused largely on Kantaras' anatomy and his lifestyle as a transsexual. Court TV covered the trial live.

Kantaras' anatomy and even his bedroom habits became a focus in the trial, which included testimony from a phalloplasty surgeon and specialized gender identity psychologists.

Michael Kantaras' lawyer Collin Vause

Linda Kantaras admitted on the stand that she married Kantaras in 1989 knowing that he was born in 1959 as Margo Kantaras, and was granted a name change to Michael John Kantaras in 1986 by a Texas judge.

But she testified tearfully that the transition was never complete.  "Michael Kantaras is a woman who thinks that he is a man," said Kantaras. "You cannot think you're a man and have man characteristics and be a natural man."

Her attorney, Caudia Wheeler, cautioned in her closing argument that a decision favoring Michael Kantaras would be "like a barnyard door coming open. If Michael can be a male because Michael thinks he is a male, and because of some surgery, your honor, then we're headed for big trouble... It will create utter chaos."

Karen Doering, Michael Kantaras' co-counsel and staff attorney at the National Center for Lesbian Rights, called Wheeler's caveat "just silly."  "I think this is a very very positive sign," she told Court TV Friday.  "This is the first case to thoroughly examine the medical aspects of transsexualism."

Other advocates hoped the case would impact more than just the law. 

"I think [the case] was really groundbreaking on both a legal and a cultural level," said Cathy Renna, news director with the Gay & Lesbian Alliance Against Defamation (GLAAD). "For once this was a story that took transgender people out of the abstract and gave them a chance to really speak about their lives."

In addition to defending the sexual identity of their client, Michael Kantaras' lawyers argued that he was simply the better parent. Linda Kantaras, they claimed, had even used her ex-husband's transsexual status to try push his children away from him.

Michael Kantaras was granted temporary custody in May 2001 after Judge O'Brien ruled Linda Kantaras had, indeed, used her ex-husband's sex change to alienate the children.

Judge O'Brien came out of retirement to oversee the bench trial.