Final answer:
The period before Chinese unification following the Zhou Era is known as the Warring States period, from about 475 to 221 BCE, marked by extensive warfare and significant philosophical development.
Step-by-step explanation:
The period at the end of the Zhou Era and just before Chinese unification is known as the Warring States period. This era, lasting from approximately 475 to 221 BCE, followed the Spring and Autumn period and is marked by heavy conflict among several states vying for power. The Warring States period was characterized by military strategies, large-scale battles involving massive armies, and the establishment of different philosophies, such as Confucianism, Daoism, and Legalism. Despite the focus on warfare, this era also fostered significant philosophical and cultural development, contributing to what is considered an "axial age" in Chinese civilization. Ultimately, the state of Qin emerged victorious, leading to the unification of China and the end of the Warring States period.
\