Isaac Komnenos

Nothing is known of Manuel's early life. His parents' identity is obscure: as Manuel's own firstborn son was named Isaac (Isaakios), the Greek scholar Konstantinos Varzos considered it likely that his father had the same name, since according to Greek custom the eldest male child is named after its paternal grandfather. Nothing is known otherwise about his life and career.

https://en.wikipedia.org/wiki/Manuel_Erotikos_Komnenos