LYON (France)

The written history of Lyon / Lugdunum starts in 43 NC when Lucius Munantius Plancus was mandated by the Senate in Rome to found a colony for some Roman citizens who had just been expelled from the nearby Vienne. Perhaps they were accompanied by veterans of one of Caesars legions, the Vth Alouette and/or veterans of Munatius Plancus himself. The chosen settlement was the hill now called La Fourvière. Around 20 - 18 BC Agrippa made it to the starting point of four Gallo-Roman roads to the river Rhine, the Channel, Aquitania and to Gallia Narbonensis. The colony was called Colonia Copia Felix Munatia Lugdunum where dunum might be derived from a heightening and lug from the Celtic deity Lug or from the word light. Excavations have proven that the majority of the town was built during the first years following the foundation. By will of Augustus, Lyon quickly became the chief town of the Lyonnaise province. Until the middle of the second century, prosperity prevailed in Lugdunum as in the empire as a whole and Lyon gradually became the economic capital of Gaul. The warehouses were filled with corn, oil and wine. Augustus created a monetary workshop in Lugdunum. The town grew to perhaps 50.000 inhabitants and was one of the two most populated towns of Gaul, together with Narbo / Narbonne. In the year 10 BC the future caesar Claudius was born in Lugdunum. Some 50 years later Lugdunum got a new name Colonia Copia Claudia Augusta Lugdunum.

In the early years the need for water in Lugdunum was covered by the rivers Saône and Rhône, on higher grounds augmented by wells and springs. But with the development of Lugdunum the need for water grew and in the first years of Augustus Lyon got its first aqueduct, the Mont d'Or which source was 10 km N of the town at a height of 370 m. The main problem of the Roman engeneers was the fact that the centre of the town laid on the La Fourvière hill on about 300 m high and surrounded by lower valleys. This kind of acropolis-like setup made the use of a hughe aqueduct bridge (over 100 high) or a so called siphon (a (series of) conduits(s) under water pressure) necessary. Because of economic reasons in such cases a siphon was preferred over an aqueduct bridge.

In the following decades more water was needed so an other three aqueducts were built, all hampered by the local low valleys. With each new aqueduct the distance between the water source and the Fourvière hill grew, from 10 km (Mont d'Or; total aquaduct length 26 km), 20 km (Yzeron, 40 km) and 26 km (Brévenne, 70 km) to 42 km (Gier, duct-length 86 km).
The four Lyon aqueducts are so interesting because of the nine (!) siphons in total. Because of the choosen trace, in the Yzeron aqueduct even a double siphon was needed which, together the double siphons in Turkey, are the only known examples in the Roman empire.

Lyon - LUGDUNUM