What is the name of the detective in Ngaio Marsh's novels?

The detective in Ngaio Marsh's novels is Roderick Alleyn. Alleyn is a gentleman detective and senior officer of London's Metropolitan Police, appearing in the long-running series created by New Zealand writer Ngaio Marsh.

He first appeared in 'A Man Lay Dead' in 1934. Across the novels, readers follow his career as he investigates murders in England and, in several stories, New Zealand. The cases often reflect Marsh's interests in theatre, painting, aristocratic society, and the tensions of her era. Alleyn eventually marries the painter Agatha Troy, who becomes an important recurring character.

Marsh wrote 32 Alleyn detective novels between 1934 and 1982, and all of her principal crime novels feature him. She is commonly grouped with Agatha Christie, Dorothy L. Sayers, and Margery Allingham as one of the Queens of Crime. A common mix-up is to choose Inspector Wexford, who was created by Ruth Rendell, or Adam Dalgliesh, who was created by P. D. James.