Wrote several drafts for a film adaptation of Stephen King's novel "The
Stand" for director George A. Romero. They were thrown out when it was decided
to adapt the novel as a mini-series, The Stand (1994), which King himself
wrote.
He was a long-term associate of director John Boorman, but they fell out when Boorman cast his own son, Charley Boorman, in The Emerald Forest (1985). Pallenberg strongly opposed this (although the performance was widely praised), and they never worked together again.
He is the son of Corrado Pallenberg, one of the most eminent doctors in Europe (and a medical adviser to the Papacy).
In 2008, Rospo and John Boorman worked together again on "Hadrian" yet to be produced. In 2015, John Boorman and Rospo are working on "CuChulainn".
Of interest: In 1970 he wrote in collaboration with Jonh Boorman as one single movie Tolkien's "Lord of The Rings".