The SPQR series is a collection of historical mystery stories by John Maddox Roberts set in the time of the Roman Republic. SPQR (the original title of the first book, until the sequels came out) is a Latin initialism for Senatus Populusque Romanus ("The Senate and the Roman People"), the official name of the Republic.
The stories are told in first-person form by Senator Decius Caecilius Metellus the Younger (born c 91-95 BC), nephew of Metellus Pius and member of the powerful Caecilius Metellus family of the Roman Senate. The stories are told in flashback-form by the old Decius, writing during the reign of Augustus Caesar. The stories range from 70 BC (The King's Gambit) to 20 BC ("The King of Sacrifices").
Decius' companions include his slaves Cato, Cassandra, and Hermes; his friends, the Greek gladiatoral physician Asklepiodes and the gangster/politician Titus Annius Milo; and his staunch enemies, the siblings Clodia and Clodius. Along the way, he is often helped by his father, as well as by Cicero and a young Julius Caesar. In later books, Decius is betrothed and then married to the (fictional) niece of Caesar, Julia Caesaris. The dates are all listed at the end of each book in the ab urbe condita calendar system.
The series includes (in chronological order):
- I: The King's Gambit (70 BC) — Decius uncovers a plot to subvert Lucullus' army in the war against Mithridates. ISBN 0-312-27705-9
- II: The Catiline Conspiracy (63–62 BC) — Decius uncovers Catiline's plot to overthrow the Republic. ISBN 0-312-27706-7
- III: The Sacrilege (62-61 BC) — Decius investigates Clodius' desecration of the Bona Dea rites. ISBN 0-312-24697-8
- IV: The Temple of the Muses (60 BC) — Decius investigates the murder of a philosopher at the Library of Alexandria. ISBN 0-312-24698-6
- "The Statuette of Rhodes" (60 BC) (short story in Classical Whodunnits 1996 edited by Mike Ashley) — Decius finds a corpse on the base of the Colossus of Rhodes. ISBN 0-7867-0418-7
- V: Saturnalia (59 BC) — Decius investigates the murder of his kinsman Metellus Celer. ISBN 0-312-32018-3
- VI: Nobody Loves a Centurion (58 BC) — Decius investigates the murder of a centurion of the 10th Legion at the start of the Gallic Wars. ISBN 0-312-32019-1
- VII: The Tribune's Curse (55 BC) — Decius investigates the murder of a tribune who curses Crassus on his way to Parthia. ISBN 0-312-30488-9
- "Mightier Than the Sword" (53 BC) — Decius investigates a murder of a victim found in the basement of a townhouse in Rome. (short story in The Mammoth Book of Historical Whodunnits 1993 edited by Mike Ashley) — ISBN 1-84119-373-9
- VIII: The River God's Vengeance (53 BC) — Decius investigates a collapsed insula, uncovering systematic fraud in the construction trade. ISBN 0-312-32319-0
- "The Etruscan House" (52 BC)— Decius investigates a senator's murder. (short story in Crime Through Time II 1998 collected by Miriam Grace Monfredo & Sharan Newman) ISBN 0-425-16410-1
- "An Academic Question" (51 BC) - Decius investigates a murder during his visit to Athens mentioned as part of his leisurely trip to Cyprus at the beginning of "The Princess and the Pirates" (short story in Past Poisons 1998 edited by Maxim Jakubowski). ISBN 0-7472-7501-7
- IX: The Princess and the Pirates (51 BC) — Decius investigates the murder of his host, the Roman governor of Cyprus, while on the island to deal with an upsurge in piracy. The princess is a young Cleopatra VII of Egypt. ISBN 0-312-33723-X
- X: A Point of Law (51-50 BC) — While running for election to the office of praetor, Decius must deal with accusations that he murdered a man who had threatened to denounce him for actions he took while on Cyprus the previous year.
- XI: Under Vesuvius (50 BC) — was released in English December 2007, published in 2001 in German translation as Mord am Vesuv. As praetor peregrinus, Decius investigates a murder near Mount Vesuvius. ISBN 978-0-312-37088-6
- XII: Oracle of the Dead (50 BC) — published in English December 2008, published in October 2005 in German translation as Das Orakel des Todes. As praetor peregrinus, Decius investigates the murders of a group of priests of Apollo during the period just before Caesar crosses the Rubicon. ISBN 0-312-38093-3
- XIII: The Year of Confusion (46/45 BC)— published in English, February 2010; published in German, January 2009. Decius examines the murders of some astronomers who had developed Caesar's calendar. ISBN 978-0-312-59507-4
- XIV: Dolabella Forthcoming
- "Venus in Pearls" (46 BC) (short story Alfred Hitchcock’s Mystery Magazine July/August 2001 p36) — Caesar hires Decius to locate his stolen breastplate before his Pompeian triumph
- "The Will" (44 BC) (short story The Mammoth Book of Roman Whodunnits 2003 edited by Mike Ashley) — Decius investigates Caesar's will following his assassination. ISBN 0-7867-1241-4
- "The King of Sacrifices" (20 BC) (short story in The Mammoth Book of Historical Detectives 1995 edited by Mike Ashley) — Livia hires Decius to investigate the murder of Julia's lover. ISBN 0-7867-0214-1
- "The Mountain Wolves" (short story in Classical Stories: Heroic Tales from Ancient Greece and Rome 1996 edited by Mike Ashley). ISBN 1-85487-812-3 [ a historical story, but not belonging to the SPQR series]
These dates are approximate because there is contradictory information within the texts. For instance, in the The Sacrilege which can be dated externally at 62 BC, Decius claims to be turning 29, indicating he was born in 91 BC. Yet in The Tribune's Curse, he finds that he was born in the same year as Marcus Porcius Cato (95 BC). In "King of Sacrifices" externally dated at 20 BC, he claims he was in his 73rd year, indicating he was born in either 93 or 92 BC. The AUC dates given in The Sacrilege, Temple of the Muses and "Statuette of Rhodes" are clearly erroneous. The Sacrilege has a clear external date and there is a strong indication that "Statuette" takes place in the same year as Saturnalia. Temple probably falls somewhere in between the other two. The author has noted that events in The Year of Confusion have been modified for dramatic effect.