Michael Gambon, the acclaimed actor known for his commanding stage and screen presence, experienced a gradual and challenging decline in his later career, according to a recent comprehensive biography. Spanning nearly 600 pages, the work explores both the highs of Gambon's performances and the difficulties he faced as he aged, revealing a complex portrait of the actor’s professional and personal struggles.

Gambon’s reputation for onstage mischief is well-documented by those who worked with him. Colleagues recall his use of prank devices such as fart machines and water pistols, as well as impromptu lines intended to unsettle fellow actors. While these anecdotes are often humorous, some witnesses suggest the behavior became tiresome or even cruel. Actress Penelope Wilton described the water pistol antics as “very tedious,” and Eileen Atkins recounted Gambon’s dismissive attitude towards matinee performances, a stance that frustrated some co-stars.

During productions, Gambon sometimes showed a loss of focus after initial successes. After the strong opening of "A View from the Bridge," for example, co-star Michael Simkins said Gambon began to “gently destroy” the show with declining performance quality, ultimately hindering plans for a New York transfer.

The biography details how Gambon’s difficulties intensified in his late 50s, notably with remembering lines. Early theatrical interventions included prompt boards and discreet earpieces through which prompts were fed, devices that were more effective in film work where multiple takes were possible. This method allowed Gambon to maintain strong performances in cinema roles, including his portrayal of Albus Dumbledore in the "Harry Potter" films following the death of Richard Harris. However, on stage these challenges became increasingly evident.

The author reveals that Gambon was eventually diagnosed with dementia, although the actor himself reportedly denied the condition, possibly due to witnessing his mother’s decline from the same illness. This late period uncovered a more vulnerable side of Gambon that contrasted with his earlier boisterous persona, exposing fears of professional exposure and personal frailty.

The biography takes an unconventional structure, interspersing the main narrative with thematic interludes that highlight lesser-known facets of Gambon’s character and career. These include a focus on his distinctive hand gestures, notably used in his film work, and his passion for fast cars, demonstrated in a memorable "Top Gear" segment where he narrowly avoided a serious accident.

The author grapples with explaining what made Gambon a great actor, collecting perspectives from colleagues and critics but concluding that the essence of his performances defies simple explanation. Similarly, the contradictions in Gambon’s personality resist neat characterization. The resulting picture is an unresolved tension fitting for a figure who seemed to embrace complexity, leaving a legacy that continues to intrigue as much as it entertains.