| Hugh | Alexander | An Irish-born British cryptanalyst. |
| Princess | Alexandra | The Queen's cousin and a working member of the Royal Family. |
| Jane | Austen | An English novelist. |
| Johann S. | Bach | German composer and musician of the Baroque era. |
| Keith | Batey | British cryptographer. |
| L. Frank | Baum | American children's writer, editor, journalist, screenwriter. |
| Ingrid | Bergman | Swedish actress. |
| Mr. | Birch | Miss Senyard's acquaintance. |
| Wren | Bishop | A girl who was seeing an American officer. |
| Robbie | Blaine | Sheila's acquaintance. |
| Mrs. | Bowden | Mrs. Finch's acquaintance. |
| Mr. | Bradshaw | A paymaster commander. |
| W. | Breisbach | Osla's acquaintance. |
| Guinevere | Brodrick | Countess of Midleton. |
| Charlotte | Bronte | An English novelist and poet. |
| Charlotte | Brontë | An English novelist and poet. |
| Daisy | Buchanan | The author of Insatiable. |
| Lewis | Carroll | An English writer, logician, Anglican deacon and photographer. |
| Andrew | Cavendish | 11th Duke of Devonshire. |
| Mrs. | Chadwick | One of Beth's married sisters. |
| Thomas | Chalmers | Scottish minister, professor of theology, political economist. |
| Agatha | Christie | English mystery and detective writer. |
| Winston | Churchill | British statesman served as Prime Minister of the United Kingdom. |
| Mabel | Churt | A girl striving to make a better life for her mother and young sister. |
| Mrs. | Churt | Mab's mother. |
| Joan | Clarke | English cryptanalyst and numismatist. |
| John | Cornwell | Osla's Good Samaritan. Aka: J.P.E.C. |
| Bing | Crosby | American singer, actor and comedian. |
| Andrew | Cunningham | A British Admiral of the Fleet. |
| Agnus | Dei | The name of the machine. aka: Aggie. |
| Alastair | Denniston | British cryptographer and Royal Navy Commander. |
| Charles | Dickens | English writer and social critic. |
| Karl | Dönitz | German admiral during the Nazi era who succeeded Adolf Hitler. |
| John | Donne | English poet, scholar, soldier. |
| Caroline M. | Douglas-Scott | Daughter of the 8th Duke of Buccleuch and Mary Lascelles. |
| Arthur Conan | Doyle | Scottish physician and author. |
| Daphne | du Maurier | British writer. |
| Ian | Farquhar | Brodrick's acquaintance. |
| Miss | Fenton | Sally's acquaintance. |
| Bethan | Finch | A spinster under the thumb of her overbearing mother .aka: Beth. |
| Mr. | Finch | Beth's father. |
| Muriel | Finch | Beth's mother. |
| Greta | Garbo | Swedish-American actress. |
| Valerie | Glassborow | Kate Middleton's grandmother. aka: Val. |
| Ian | Graham | A journalist. |
| Francis C. | Gray | Foreign Office official and mediocre poet. |
| Thomas | Hardy | British actor, screenwriter and producer. |
| Billy | Hartington | Future Duke of Devonshire. |
| Norman | Hartnell | The leading British fashion designer, for ladies of the royal family. |
| David Milford | Haven | Philip's friend. |
| Dame Myra | Hess | British pianist. |
| Adolf | Hitler | Leader of the Nazi Party. |
| A.E. | Housman | British classical scholar and poet. |
| Geoffrey | Irving | Mab's acquaintance. |
| Ken | Johnson | A swing band leader and dancer. aka: Snakehips. |
| Andrew | Kempton | Mab's acquaintance. |
| Osla | Kendall | The wartime girlfriend of Prince Philip. |
| Phyllida | Kent | One of BP's workers. |
| Dillwyn Alfred | Knox | Beth's boss. |
| Veronica | Lake | American film, stage, and television actress. |
| Vladimir | Lenin | Founder of the Soviet Union. |
| Alice | Liddell | The registered name of a patient. |
| Princess | Margaret | Countess of Snowdon. |
| Miss | Marple | One of Christie's best-known characters. |
| Sheila Jean | McGee | Harry Zarb's wife. |
| Alexander | McQueen | British fashion designer and couturier. |
| Kate | Middleton | Duchess Of Cambridge. |
| Glenn | Miller | American big band musician, arranger, composer and bandleader. |
| Deborah | Mitford | The Dowager Duchess of Devonshire. |
| Edward | Molyneux | Paris-based British fashion designer. |
| Bernard | Montgomery | British Army officer, Commander of Allied forces. |
| Lord | Mountbatten | British Royal Navy officer. He was Prince Philip's uncle. |
| Philip | Mountbatten | Formerly Prince Philip of Greece. |
| Benito | Mussolini | Former Prime Minister of Italy. |
| Isaac | Newton | English mathematician, physicist, astronomer, theologian. |
| Sarah | Norton | Osla's friend. aka: Sally |
| Rolf | Noskwith | A cryptographer at the Bletchley Park British military base. |
| Scarlett | O'Hara | A protagonist in the novel Gone with the Wind. |
| Wilfred | Owen | English poet and soldier. |
| Wilfred | Owen | English poet and soldier. |
| Hercule | Poirot | Agatha Christie's detective. |
| Hercule | Poirot | A fictional Belgian detective by Agatha Christie. |
| Fanny | Price | The heroine in Jane Austen's 1814 novel. |
| Mrs. | Riley | One of Beth's married sisters. |
| Margaret | Rock | Beth's supervisor. aka: Peggy. |
| Franklin D. | Roosevelt | 32nd president of the United States from 1933 until 1945. |
| Friedrich | Schiller | German poet, philosopher, historian, and playwright |
| Mr. | Scopelli | Harry's acquaintance. |
| Miss | Senyard | Osla's supervisor. |
| Dr. | Seton | Beth's physician. |
| William | Shakespeare | English playwright and poet. |
| Mike | Sharpe | Mab's second husband. |
| Wren | Stevens | Mab's co-worker. |
| Bram | Stoker | Irish novelist and short story writer. |
| Giles | Talbot | A Bletchley Park's worker. |
| William | Thackeray | A British novelist, author and illustrator. |
| Commander | Travis | The madhouse new warden. |
| Alan | Turing | Mr. Zarb's acquaintance. |
| Peter | Twinn | Beth's new boss. |
| Oscar | Wilde | Irish poet and playwright. |
| Angus Frank | Wilson | An English novelist and short story writer. |
| Henry Omar D. | Zarb | Beth's acquaintance. aka: Harry. |
| Albert | | Prince of Consort. Queen Victoria's husband. |
| Alice of Battenberg | | Mother of Prince Philip and mother-in-law of Queen Elizabeth II. |
| Arthur | | One of Francis Gray's friends. |
| Asa | | A BP worker. |
| Boadicea | | The queen of the British Celtic Iceni tribe. |
| Boots | | Beth's dog. |
| Charlie | | A young naval officer. |
| Christopher | | Harry Zarb's son. |
| Claire | | Beth's co-worker. |
| Cohen | | Harry's friend. |
| Edward | | Mab's son. aka: Eddie. |
| Elizabeth Alexandra Mary | | Full name of Elizabeth II - the Queen of the United Kingdom. |
| George | | Philip's cousin. The King of Greece. |
| Georges | | One of Francis Gray's friends. |
| Harold | | An officer working at BP. |
| Henry V | | King of England. |
| Hinsley | | One of the workers at Bletchley Park. |
| Jack | | Sheila's lover. |
| Jane | | Osla's co-worker. |
| Jean | | Beth's co-worker. |
| Jimmy | | Stevens's fiancé. |
| Kit | | One of Francis Gray's friends. |
| Lilibet | | Philip's cousin. |
| Lucy 1 | | Mab's sister. |
| Lucy 2 | | Mab's daughter. |
| Marina | | Philip's cousin. |
| Maurice | | Harry's cousin. |
| Molyneux | | A designer. |
| Napoleon | | French general and emperor. |
| Napoleon | | French general and emperor. |
| Olive | | Dilly Knox's wife. |
| Pinstripes | | Travis' acquaintance. |
| Queen Victoria | | Queen of the United Kingdom of Great Britain and Ireland. |
| Rowe | | A matron in the asylum. |