Yes, "Seven Kings Must Die" is a sequel to the series "The Last Kingdom." This film continues the story of Uhtred of Bebbanburg, following the events of the series, which is based on Bernard Cornwell's "The Saxon Stories." The movie wraps up Uhtred's journey and explores the historical context of England's unification during the Viking Age. It was released in April 2023 and serves as a conclusion to the narratives established in the series.

"The Last Kingdom" is actually a historical drama television series based on Bernard Cornwell's "The Saxon Stories" novels, rather than a movie. Set in the late 9th century, it follows Uhtred of Bebbanburg, a Saxon nobleman captured and raised by Vikings after his village is invaded. Torn between his Saxon heritage and Viking upbringing, Uhtred seeks to reclaim his ancestral home while navigating the complex political landscape of England during the Viking invasions. The series explores themes of loyalty, identity, and the struggle for power.

In "The Last Kingdom: Seven Kings Must Die," Uhtred, portrayed by Alexander Dreymon, is depicted as being in his late 40s to early 50s. The film is set after the events of the series, which concludes with Uhtred's journey through the turbulent times of the late 9th and early 10th centuries. While his exact age is not specified, the character's maturity and experiences reflect a significant passage of time since the earlier seasons of the series.

"Seven Kings Must Die" is a historical drama film that continues the story from the Netflix series "The Last Kingdom," which is based on Bernard Cornwell's "The Saxon Stories." While the film incorporates real historical events and figures from 9th and 10th century England, it also includes fictional elements and dramatizations for storytelling purposes. Thus, while inspired by true events, it should not be taken as a strict historical account.