Mr. Walton was born in Market Harborough, England, and raised in Coventry, England.
He studied law at University College, London, England, and was admitted as a solicitor in England in 1966, and for the entirety of his English legal career practiced at W.H. Thompson, the foremost trade union law firm, where be became a managing partner in the 1980s.
"There Simon made an enormous contribution to the rights of workers worldwide by developing a legal action for coal miners to be compensated for lung diseases suffered underground and not diagnosed until years later," said his wife of 14 years, Nicole Schultheis, a Baltimore trial lawyer.
It was while attending a trial lawyers' conference in Toronto in the early 1990s that Mr. Walton became acquainted with his second wife.
"We were attending a banquet and seated at small tables of four. Someone said, 'Oh, there's Simon, and he likes wine, and we know that you like wine,' so I was placed next to him," Ms. Schultheis said.
"That's how it happened. He moved to Baltimore, passed the Maryland Bar, and we married in 1994," she said.
Mr. Walton and his wife established the law firm of Schultheis & Walton P.A., which specialized in representing clients harmed by defective drugs or medical devices.
"He also concentrated his litigation in the public interest and on behalf of the disabled," Ms. Schultheis said.
"His skills as an advocate and his kindnesses toward those in need of representation in difficult and complex cases brought him admiration from the bench and bar," she said. "He had a big heart and a strong heart."
Andrew D. Levy, a Baltimore attorney, is a longtime friend.
"He was a believer. Plaintiffs' lawyers are so often portrayed as doing what they do simply for the money, but not Simon," Mr. Levy said. "He truly believed in victims' rights. These are the victims who have been left standing because their rights had been violated."
Stephen J. Cullen, an attorney with Miles & Stockbridge in Towson, is also a longtime friend.
"Simon was such a decent human being, and when he came here immediately gained the respect of both the bench and the bar," Mr. Cullen said. "He was a lawyer who wanted to help those who couldn't help themselves. He was absolutely committed to the underprivileged and the poor and those who couldn't afford legal representation."
Wayne M. Willoughby, an Owings Mills attorney, is president of the Maryland Association for Justice, formerly the Maryland Trial Lawyers Association.
"Simon's death is so very sad. He was a great man and a truly compassionate and wonderful attorney," Mr. Willoughby said.
Mr. Walton had chaired the organization's pro bono and diversity committees.
"Simon's concern for our society extended beyond working to provide the needy access to the courts and bringing diversity to the bar," Mr. Willoughby wrote in a statement to MAJ members announcing Mr. Walton's death.
"For many years, Simon chaired MAJ's charity programs for purchasing and distributing free smoke detectors and free bicycle helmets to economically disadvantaged families and children," he wrote.
After the terrorist attacks of Sept. 11, 2001, Mr. Walton championed the "Trial Lawyers Care" program whereby MAJ members joined their legal colleagues from around the nation in providing free legal representation to the victims and to families who were affected by the attacks.
"His was a leading role in what became the biggest pro bono representation project in American history," Ms. Schultheis said.
Additionally, his work with Access Maryland led to numerous institutions and businesses across Maryland being brought into compliance with the Americans with Disabilities Act.
In 1996, Mr. Walton coordinated the work of 15 attorneys who volunteered with Access Maryland and identified businesses that were in violation of the Americans with Disabilities Act.
"Given that Towson Town Center is a splendid modern facility, it really ought to comply with the law," Mr. Walton told The Daily Record in a 1996 interview, regarding the fact that its restrooms were not accessible to the disabled, despite being advertised as such. "It's another regrettable instance in which disabled people are rather forgotten," he said.
In a 2001 case regarding wheelchair access to the Bank of America's historic branch at 10 Light St. in downtown Baltimore, Mr. Walton eloquently explained to U.S. District Judge Marvin J. Garbis, who presided over the case, "Your honor, it may be a golden tower, but it has feet of clay."
"Simon was an unrivaled and rounded human being, loving father and generous friend," Mr. Cullen said. "He was also an expert in French wine and Scottish single malt whiskeys. He had one of the finest wine cellars in Baltimore, plus a great cache of single malt scotches that he would share with anyone."
Mr. Cullen said his friend never had any trouble having his sidewalk shoveled after a snowstorm.
"He'd come out with drinks, so consequently people were lining up to shovel his walkways," Mr. Cullen said, laughing.
Mr. Walton was an avid collector of first-day cover stamps, maps and World War I Goss commemorative china.
"He was a man of great knowledge and repartee," Mr. Cullen recalled.
True to his British roots, friends said, Mr. Walton embraced the life and works of Robert Burns, the Scottish poet.
In the 1990s, he established the Baltimore Burns Society and reveled in hosting the society's annual banquet in his Northwood home that often included 45 guests or more.
"His life epitomizes Robert Burns' sentiment, 'that Man to Man, the world o'er / Shall brothers be for a' that,' " Mr. Cullen said.
Mr. Walton also enjoyed spending time at a second home in the Bordeaux region of France.
Services will be held at 10 a.m. Tuesday at Sterling-Ashton-Schwab-Witzke Funeral Home, 1630 Edmondson Ave., Catonsville.
Also surviving, are three daughters, Rachel Walton Bream of London, Jessica Walton Ussher of Bristol, England, and Cecile Marie Walton of Baltimore; his mother, Hilda Walton of Coventry; two sisters, Claire Smith of Coventry and Amanda Walton of Serbia; and three grandchildren. A 1968 marriage to the former Marianne Scott ended in divorce.