Philanthropist Brooke Astor changed her will and left most of her $198 million estate to her only child rather than charity because her dislike of his third wife gradually softened, a defense lawyer said Tuesday.

Attorney Frederick Hafetz said Astor's wills from 1953 to 1993 gave almost everything to her son, Anthony Marshall, but later wills directed most of her money to charity "because of the relationship with Tony's wife, Charlene." The Marshalls married in 1992, two years after she divorced an Episcopal priest in Maine, where Astor had a summer home.

"There was no love lost between Brooke Astor and Charlene Marshall," Hafetz, Anthony Marshall's lawyer, said in opening remarks in Manhattan's state Supreme Court, where the son is charged with stealing from his mother. He said Astor "simply did not like her."

But Astor slowly realized Marshall's wife made him happy, Hafetz said, so she "reverted to her previous pattern and decided to leave her money to her only son."

Assistant District Attorney Elizabeth Loewy had argued Monday that Astor's last will, on Jan. 30, 2002, reflected her decades-long plan to leave most of her estate to her favorite charities, her "crown jewels," not to Marshall.

Loewy said Marshall took advantage of his mother's debilitated mental state to fraudulently add three amendments to the socialite's 2002 will, on Dec. 18, 2003, on Jan. 12, 2004, and on March 3, 2004. She said these amendments give Marshall most of his mother's estate.

He did this after siphoning off millions of dollars in cash and property without the Alzheimer's disease-stricken social doyenne's knowing consent, the prosecutor said.

Loewy said Astor's signature on the Jan. 12 codicil is a forgery by Marshall's co-defendant, Francis X. Morrissey, a lawyer he hired after he had fired Astor's previous lawyer.

Marshall, 84, is charged with grand larceny and conspiracy. He faces a maximum sentence of 25 years if convicted of first-degree grand larceny, the top count.

Morrissey, 66, faces up to seven years if he is convicted of the top count against him, second-degree forgery. His lawyer contends the prosecution's handwriting expert will be discredited.

Both defendants have pleaded not guilty.

Hafetz said his client did not need to steal from his mother because he was going to inherit everything anyway. He said Astor, who died in August 2007 at age 105, wanted Marshall to enjoy the social prestige that her third husband, Vincent Astor, had made possible for her.

He said Astor's wills showed for 40 years she intended to leave most of her estate to Marshall, not to charity as prosecutors contend.

"Her plan had been to give that money to Tony," he said.

Hafetz said Astor's will was the socialite's "obsession," and she changed it 38 times before she died.

"She changed her will," he said, "like people change their socks."