Mark Seaman

Mark Seaman has spent more than forty years as a successful Radio and Television Broadcaster and Actor. He has managed radio stations with both the BBC and the commercial sector, including Premier Radio in London where he acted as Programme Director and Presenter for the first year of the station’s life.

More recently he has established himself as an award winning Playwright and Director, whilst continuing with occasional broadcasting and acting work. He played the role of Sir John Tressida in the latest BBC production of Poldark. Mark has a number of published manuscripts that enjoy regular production and stage performances both at home and abroad.

‘An Oath Betrayed,’ is Mark’s third novel and his second with The Book Guild. His earlier publications, ‘A Corner of My Heart,’ and ‘The Family Tree,’ were well received and gained positive reviews. He is pleased to be working with The Book Guild again and has high hopes that ‘An Oath Betrayed,’ will prove to be his most popular work to date.

Details about Mark’s earlier career are available through his website    

His play manuscripts can be found at

Mark is married with three children.    

Mark Seaman's Books

ISBN: 9781835740484


An Oath Betrayed

28 Sep 2024

Growing up together in the early 1900’s in the London Docklands, Harry and Karl forge an unbreakable friendship. With their fathers working as dockhands, both families struggle to survive on low wages and poor living conditions.

Facing unemployment and destitution following a dock strike in Germany, Karl’s parents moved to England for a better life, hoping to raise their son in an environment of love and security. However, Harry’s homelife is dominated by violence and drunken cruelty inflicted by his father. Shared dreams of a life far away from the grime and deprivation of the shipyards see the two friends swear a lifetime oath of allegiance to one another.

As time passes, the boys grow ever closer until a horrific accident threatens to tear their friendship apart. Struggling to maintain their alliance and with the advent of war, Karl returns to Germany, while Harry joins the British Army. By a strange turn of events and with war raging across Europe, the two meet again.

Will memories of their childhood pledge prove enough to overcome their differences, or has the bond between them been broken forever?    


Mark Seaman, married with three children, is a successful radio and television broadcaster, playwright, and author, with several award-winning manuscripts produced both nationally and internationally. An Oath Betrayed is his second publication with The Book Guild, following the critical success of A Corner of My Heart. Details of Mark’s career can be found at and his play manuscripts are available through