When did the great migration of peoples begin?

The great migration of peoples began with the arrival of the Huns to the northern borders of the Roman Empire in the 4th century. This, in turn, led to the movement of the Germanic tribes to the west and southwest of Europe. Thus, the borders of the Roman Empire literally cracked at the seams. This ultimately led to the decline and collapse of Rome. Although in a broad sense, the movement of peoples began as early as the 3rd century BC. due to population growth, climate change and a lack of free land.