K3LTC.com Radio History

Polybius

note: indented text was not read over the air

Tonights story is set in ancient Greece and though it may seem at first to have nothing at all to do with our modern hobby of radio, I will explain how it does indeed relate. In 200 BC Polybius was born to the son of a wealthy land owner. They lived in a large urban center in the south of Greece known as Megalopolis and as his father was a member of the governing council and later a general in the Achean League, Polybius observed first hand the affairs of that place and time. By the age of 30 Polybius had been elected as a cavalry officer so we know his star was also rising.

The Romans at that time were at war with the northern Greek state of Macedon. Macedon, in the North of Greece, was considered "barbarian" and "uncultured" to many Greeks in the south and Polybius didn't even consider them true Greeks. Alexander the Great of Macedon who spread Greek culture across the known world some 150 years prior must have been rolling in his grave!

After Alexanders death, the Greek states in the south had begun to resent Macedonian rule.

As members of the Achean League, Polybius and his father both were opposed to Macedon but also they didn't want to end up ruled by Rome. Polybius' father argued for neutrality in the Macedonian conflict. The Romans didn't trust the southern Greeks and arranged for 1000 Greek nobles to be taken back to Rome as hostages to ensure the southern Greek states remained neutral. Polybius was among them. Because he was highly educated and cultured, he was soon employed by rich Romans to teach their sons.

Polybius tutored one such Roman, a young man named Scipio. This Scipio the younger was destined to become a great general and win many battles in the Punic Wars and throughout his rise, Polybius was his counciller. Even after Rome released the Greek hostages in 150 BC, Polybius, then 50 years of age, chose to continue campaigning with Scipio and record his conquests and deeds in the Roman war against Carthage.

Polybius is understood today as the forefather of scholarly, painstaking historical research in the modern scientific sense although it is clear from his extensive writings that he had come to agree with and chose to represent the Roman viewpoint favorably.

Polybius believed that a historian should only rely on primary sources, that history could only be understood in context, that historians had an ethical duty to the truth, and that a historian should posses political as well as geographical experience. He often travelled to interview witnesses or was a witness to events himself, he discussed the conditions that led to events and didn't just relate them in a boring list.

In Chapter X of Polybius' Histories, originally a work of some 40 volumes, he turns from cataloging the grand deeds of his Roman patron in the war with Carthage to events in his native Greece. The Romans had partnered with several Greek tribes against King Phillip V of Macedon. When Rome's allies began threatening the Achaen League in the South they sent entreaties to the Macedonians for aid. King Philip realized he now had to be wary of invasions from all directions and he needed to gather intelligence from the field to decide how best to move his armies.

Polybius writes that Phillip then sent messengers to three separate locations around the Aegean Sea with orders to report everything that happened by means of fire signals that would be visible from a mountain in Thessaly. Here Polybius stops his narrative to discuss (for five whole chapters) the art and practice of sending fire signals. He describes the importance of this messaging system, the problems with it, and then offers his own improvements to the system of long distance communication.

In English translation he writes "The method of signalling by fire is of the highest utility in the operations of war and I think I shall be doing a service to give an account of it given its great importance. Timeliness is critical in all undertakings, but most of all in war and among all the things which enable us to quick action nothing is more efficacious than fire signals because they convey intelligence about what has just happened and sometimes of what is happening in the present moment; and if we make good use of them we can get information which would otherwise be three or four days' journey off or more and with this information be sooner to proivde aid where it could otherwise not be hoped for."

Polybius describes how fire signals had been used since the deep past to convey pre-arranged messages much like our own "One if by land, two if by sea" from American history, but he observed that this method was very limiting. It was impossible to transmit information about unexpected occurences such as the number of citizens who had gone over to the enemy or to provide the name of someone who may have betrayed the cause. Nothing could be tranmitted that had not previously been conceived and planned for.

He discusses a slight improvement to the fire signal system made 150 years before based on the timed draining of a pair of large earthenware water vessels marked with several pre-arranged messages but pointed out that it suffered the same problem as the more ancient system.

He related an improved fire signal method devised by two men he names as Cleoxenus and Democlitus which allowed for the transmission of individual letters and he offered a further improvement to that method which he invented himself. The new method allowed for the sending of any message without the need to agree upon meanings before-hand.

Polybius described the system as follows. Each location that would act as a signal beacon consisted of two walls at the height of a man, one to the left and one to right of some divider that made it easier for a viewer at a distant beacon to tell which side was which. The walls had 5 torch holders each affixed to them, which made it possible for the beacon operator to place up to 5 lit torches on the walls on either side of the divider (up to 10 lit torches at a time).

Both beacon operators had at their disposal 5 plates each with five letters of the alphabet inscribed on them the Greek alphabet having 24 letters in all. The number of torches on the left-hand wall of the "transmitter's" beacon determined the plate number to use (1 torch meant use plate 1) and the torches on the right-hand side indicated the desired letter on that specific plate (3 torches meant use the third letter).

The transmission of a message started as follows: the "transmitter" put up two torches and the "receiver" confirmed by doing the same and then both operators brought down the torches. Then, for instance, if two torches were put up on the left wall and four on the right wall, the receiver would know that the letter was on the second tablet in the fourth position. He could decode the message one letter at a time until the entire message had been sent.

Polybius' improvement to this system was subtle. He suggested the letters be arranged in a 5 by 5 grid so they could be looked up easily as an X, Y coordinate. This made reference easier and could be fit onto a single reference plate. This has come be known as a Polybios Square and while Polybios did not design it to be used as a cipher, it has served as the basis for some forms of cryptography.

Here Polybius is describing the very first true digital optical telegraph system some 2200 years ago! And it was digital in the sense that discrete numbers were used to represent characters. Optical telegraph systems sometimes referred to as "Semaphore" being the use of flags or symbols on towers to transmit messages over distance by sight wouldn't come into use again until the late 1700s. Semaphore a word from the early 1800s is constructed from two Greek words: Sema which meaning "sign" and Phoros meaning "bearer".

The text does not relate what messages King Phillip's beacon operators may have transmitted or which method they used. Polybius continued travelling and documenting the events of the day for many years until his death at 82 after a fall from a horse.