The two discoveries that brought a revolution in early man's life are:
1) Agriculture - It helped the early man to produce its own food. this innovation made possible new flux of innovations and ideas the husbandry and domestication of all modern cattle and pets (except dogs), the formation of soldiers and wars, the money, the origin of religion, writing and all the very basis of modern life. Developing all these new outcomes would be impossible without the cooperation and organized structure of agricultural societies.
2) Language and paintings - Language helps them to communicate with each other and painting which they did at that time helped Historians today to know about their life, language, etc.
The Germanic tribes were able to invade the Britain because
of the western half has crumbled by which they were able to push the Romans
out, where in, Romans has taken hold of the Germanic people and by pushing them
out, they have the power to invade the Britain.
B, but to be exact it was 1402
