Retired Army Maj. Gen. William Shepard Biddle, 80, a staff officer and decorated combat veteran of World War II who has been a resident of Northern Virginia since 1956, died Saturday at the Woodbine nursing home in Alexandria. He had arteriosclerosis and Alzheimer's disease.

During World War II, Gen. Biddle served in Great Britain and North Africa and later commanded the 113th Mechanized Cavalry Group when it landed in Normandy in June 1944. The unit later was attached to the Ninth Army and made contact with the Red Army near the Elbe River in April 1945.

In 1947, Gen Biddle was assigned to Washington and became deputy chief of the plans ant policy group of the Army General Staff. His other post-war duty included assignments in Europe, Japan, and Korea, and as deputy commanding general of the Fifth Army.

After retiring from active duty in 1960, he returned to Washington and joined Washington Consultants. In 1962, he began a four-year stint as commandant of cadets at the Pennsylvania Military College in Chester, Pa.

He had lived in Alexandria since 1966 and was head riding instructor at the Rock Creek Stables in Washington from 1969 to 1972. He also was a member of the board of the Washington International Horse Show.

Gen. Biddle's military decorations included two Distinguished Service Medals, the Silver Star Medal, the Legion of Merit, and the Bronze Star Medal.

Gen. Biddle was born in Michigan and was a 1923 graduate of the U.S. Military Academy at West Point. He served in the Panama Canal Zone and as an assistant military attache in London and Paris before World War II.

Survivors include his wife, the former Madelin Land of Alexandria; three daughters, Susan Dayton Biddle of Vail, Colo., Harmon Biddle of Washington, and Christina Biddle Maher of Denver; a sister, Margaret B. Parker of Portland, Ore., and one grandchild.