Year 578 (DLXXVIII) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar. The denomination 578 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
Byzantine–Sassanid War: A Byzantine army under command of Maurice (magister militum per Orientem) invades Upper Mesopotamia, and raids on both sides of the Tigris. He deports 70,000 captives from Hyrcania to Cyprus, and installs military colonists to guard the strategic locations.
October 5 – Emperor Justin II dies after several periods of insanity. On the advice of his wife Sophia, he has raised his general Tiberius to the rank of co-emperor (Caesar). From December 574 he has ruled jointly with Sophia, and now succeeds them as emperor of the Byzantine Empire.
Europe
Reccopolis (modern Zorita de los Canes) in Hispania is founded by King Liuvigild, in honour of his son Reccared.
Asia
Summer – Emperor Wu Di engages in military campaigns on two fronts: against the invading Göktürks to the north and against the Chen Dynasty in the south.
Wu Di, age 35, dies from an illness, and is succeeded by his eldest son Xuan Di as emperor of Northern Zhou.
Kongō Gumi, the world's oldest construction company (578–2006), is founded in Osaka (Japan).
Deaths
Abdul Muttalib, grandfather of Islamic prophet Muhammad
Bhavyaviveka, Indian Madhyamaka scholar (approximate date)