"He was a champion for fair housing and after retiring from federal service, he served as associate director of Baltimore Neighborhoods Inc., investigating housing discrimination complaints and enforcing laws prohibiting discrimination in housing," said Ms. Dyer.

Mr. Dyer also served on the boards of Greater Baltimore Community Housing Resource Board, Belair-Edison Housing Service and Citizens Planning and Housing Association. After stepping down from Baltimore Neighborhoods, he continued working as an independent fair-housing consultant.

"He was an expert on the Fair Housing Law and often spoke to Realtor groups about the law," said Michael L. Marks, who lives in Mount Washington. "He was committed to social justice and the arts he so loved."

Oscar Melvin was a longtime friend and colleague who retired from Baltimore Neighborhoods in 1991.

"He had no trepidation about doing what was right. He was dedicated to fair housing, and he made the world not a little better but a lot better," said Mr. Melvin. "He was a perfect gentleman. I have nothing but fond words and memories of Martin. He was a beautiful person."

In his Windsor Hills neighborhood, Mr. Dyer was an active member of the neighborhood association, where he had served as vice president, a board member and was editor of the community newsletter, and was co-author of "Windsor Hills: A Century of History 1895-1995."

Published in 1995, the book told the history of a community that had been a white, gentile enclave until the arrival in 1910 of the first Jewish residents. African-Americans began moving into the community in 1955.

The peaceful integration was one of the reasons Mr. Dyer remained in the neighborhood.

"It was an organized effort by the neighborhood to stem white flight," Mr. Dyer told The Baltimore Sun in a 2004 interview.

Mr. Dyer remained active at St. John's College, where he was a member of the Board of Visitors and Governors and also was an active member of an advisory committee to recruit and retain minority students.

"He volunteered to help the college with diversity issues and wanted St. John's to keep the promise it made after World War II on diversity," said Ms. Goyette.

"Martin was a dignified, articulate and gentle man. He was a role model for us here at the college. He could make confrontations work for everyone when it came to diversity and issues regarding race," she said. "I like to think that Martin was so helpful to us in how we thought about race, our approach and how the institution moved forward."

In recognition of his long record as a volunteer, St. John's initiated the Martin Dyer Book Fund in 1997, which helps students meet the expense of the Great Books that are integral to the college's curriculum.

Mr, Dyer also volunteered his legal skills and drafted the application for federal recognition for the Pokanoket tribe of the Wampanoag Nation.

He was a lover of art, classical music and opera, and was a member of the Peabody Choir. He was a founding member of the board of directors of the James E. Lewis Museum of Art Foundation at Morgan State University and had served as president of the board of Young Audiences of Maryland.

Mr. Dyer was a gourmet chef and assisted with his wife's catering business, Fine Foods for Small Feasts. The couple also enjoyed entertaining and were known for their New Year's Day open house.

He was an avid traveler and book collector.

Because he was born on Christmas Day, he held the holiday "in special regard," his daughter said.

"Every year, he decorated his home with numerous trees and dioramas. He donated many decorations and trees to Our House Family Support Center in Cherry Hill," said Ms. Dyer.

For years, at Christmas, he worked at the Calico Cat, a Woodlawn gift shop, where he made miniature Christmas trees decorated with flowers.

At Mr. Dyer's request, no services will be held.

In addition to his wife and daughter, Mr. Dyer is survived by another daughter, Mya Starling of New York City; and a sister, Alma Lawson of Ashburton.