Homo erectus and the Acheulean technology appear 1.7 million years ago
The origin of Homo erectus is rather uncertain. What is known is that by 1.78 million years ago Erectus inhabited East Africa, there are remains of them dated 1.7 million years in West Asia, by 1.81 million years ago they were living in the island of Java in Indonesia, and by 1.4 million years ago Spain was their territory.
The only thing we can say for sure is that Homo erectus arose from a population of Australopithecus afarensis (the species to which Lucy belongs) who were small brained and lived in the savannahs which covered North and East Africa, and Southeast Asia, 2 million years ago. Erectus coexisted with Afarensis, a species that disappeared 500 thousand years later.
By 1.5 million years ago, Homo erectus lived in vast areas of the Afro-Asian supercontinent and had already dominated a new technology.
They were carving beautiful hand axes known as Acheulean technology. The name refers to the site where a hand-ax was found in the nineteenth century: Saint Acheul, Amiens, France. This technology survived for millions of years and was still used until very recently. There are Acheulean stone tools as recent as 8 thousand years old.
Some populations of Homo erectus, known as Homo ergaster, stayed in Africa and were our ancestors who evolved and became Homo sapiens around 250 thousand years ago.