According to a statement issued by her lawyer, Bernard Clair, Ms. Giuliani “prefers to maintain her silence about the reasons for her filing and the causes behind the behavioral changes of her husband that have become obvious to even his most ardent supporters.”

His change in behavior often seemed at odds with the Rudy Giuliani who seemed transformed by the tragedy of Sept. 11, somehow rising above his petty gripes and personal failures to lead with the resolve of one of his heroes, Churchill.

Those close to him remember the Giuliani of September 2001, who turned away during a news conference so that people would not see him weeping; who arranged for psychiatric counseling for aides immersed in the tragedy’s aftermath; who worked hard to choose his words carefully when discussing the number of dead.