Superintendent Battle
An intelligent and successful officer of Scotland Yard, he is known for his wooden face, for he rarely shows emotion. For this man of a powerful physique, his specialty seems to be crimes of international diplomacy or politics. Nothing much is known of Battle (his first name remains unknown), except that his wife is Mary, that he has five children, and even a nephew who also works in the Yard. There are only five recorded cases of his, the first in 1925 and the last in 1944. In the last two novels he is barely featured, although something close to home allows him to solve the last case.
In the novel The Secret of Chimneys, the always optimistic Battle is faced with murder at a stately mansion called Chimneys and with a plot to control the European country Herzoslovakia. People are not what they seem here, and Battle solves the murders and aliases. Four years later, the mansion Chimneys again features prominently in a case given to Battle and the Yard, in the novel The Seven Dials Mystery. A houseguest at Chimneys is found dead one morning and his friend is found dead several days later, which prompts the heroine of the house (first appearing in The Secret of Chimneys) to investigate. She asks for Battle's help in uncovering a secret organization (the Seven Dials Society) and its connection with the murders. (One of the best of Agatha Christie novels, in J. D. Hobbs' opinion.)
In the Poirot novel Cards on the Table, he is one of four crime "experts" invited to dine with the mysterious Mr. Shaitana, who also had invited four murderers. Battle does his part in the investigations by interviewing each of the suspects and making background checks on each one. Poirot and Battle even stop one of the murderers from committing another murder.
Murder Is Easy is a classic example of Agatha Christie's penchant for evil and murder in a small town setting. Retired policeman Luke Fitzwilliam learns of four murders in the town of Wychwood, and decides to investigate. More murders happen, and Scotland Yard sends Battle to the town to aid Fitzwilliam in the arrest of the murderer.
In Battle's final story, Towards Zero, he encounters a baffling case of the murder of a wealthy woman while having her family visit for a week. While this happens, Battle is vacationing nearby with his nephew Jim, and is called in to investigate. An incident with Battle's daughter months earlier points him to the correct solution of the woman's murder.