Dylan Summerfield II was the great-grandfather of Bernice Summerfield.
Dylan was born in the early 25th century. Dylan's father Marshal Summerfield VI named Dylan after their ancestor Dylan Summerfield I in the hope that he would gravitate towards a bohemian life.
Dylan had multiple children, but in 2455 he was arrested for sleeping with non-humans and they were taken away from him.
In the late 26th century, Christine Summerfield learned about Dylan when she read the Summerfield family tree. (PROSE: Dead Romance)