Marcomannic Wars: The Roman army in Moravia is encircled by the Quadi, who have broken the peace treaty (171). In a violent thunderstorm emperor Marcus Aurelius defeats and subdues them in the so-called "miracle of the rain".

The Marcomannic Wars were a series of wars lasting from about AD 166 until 180. These wars pitted the Roman Empire against principally the Germanic Marcomanni and Quadi and the Sarmatian Iazyges; there were related conflicts with several other Germanic, Sarmatian, and Gothic peoples along both sides of the whole length of the Roman Empire's northeastern European border, the river Danube.

The Roman army served ancient Rome and the Roman people, enduring through the Roman Kingdom, the Roman Republic, and the Roman Empire, including the Western Roman Empire and the Eastern Roman Empire. It is thus a term that broadly spans approximately 2,206 years, during which the force underwent numerous permutations in size, composition, organization, equipment and tactics, while conserving a core of lasting traditions.

Moravia is a historical region in the east of the Czech Republic and one of three historical Czech lands, with Bohemia and Czech Silesia.

The Quadi were a Germanic people during the Roman era, who were prominent in Greek and Roman records from about 20 AD to about 400 AD. By about 20 AD they had a kingdom centred in the area of present-day western Slovakia, north of the Roman border on the Danube river. After probably first settling near the Morava river the Quadi expanded their control eastwards over time until they also stretched into present day Hungary. This was part of the bigger region which had been partly vacated a generation earlier by the Celtic Boii, and their opponents the Dacians. The Quadi were the easternmost of a series of four related Suebian kingdoms that established themselves near the river frontier after 9 BC, during a period of major Roman invasions into both western Germania to the northwest of it, and Pannonia to the south of it. The other three were the Hermunduri, Naristi, and the Quadi's powerful western neighbours the Marcomanni. Despite frequent difficulties with the Romans, the Quadi survived to become an important cultural bridge between the peoples of Germania to the north, the Roman Empire to the south, and the Sarmatian peoples, most notably the Iazyges, who settled in the same period on the great plain between the Danube and the Tisza rivers.