BackgroundThe name itself is British in origin. It is related to the family name "Beeston", which is also the name of a castle in Cheshire. Its first historical mention occurred around the year 1220. 
Several Besons arrived in the new world in the mid seventeenth century. They originally settled in Maryland and Virginia, and Besons served on both sides of the American Civil War. 
Canon in The Siege of Abigail Beson
Abigail Beson's first name was given in honor of her paternal grandmother, Abigail Fleischer. Like many Germans, Abigail Fleischer immigrated to the Americas in the early 19th century. The elder Abigail initially settled in Pennsylvania, but fell in love with a British man named Harland Beson. They married and moved to Virginia.
Abigail Fleischer took her husband's name when they wed, but being both stubborn and proud of her German heritage, she insisted on pronouncing the family name beh-zohn, as it is spoken in the German word "besonders" meaning "especially" or "particularly". Her children (including Osman, our hero's father) adopted this pronunciation.
 Beson Name Meaning & at Ancestry.com