The Classical Age refers to the period when much of the Indian Subcontinent was reunited under the Gupta Empire (ca. 320 CE–550 CE). This period is called the Golden Age of India and was marked by extensive achievements in science, technology, engineering, art, , literature, logic, mathematics, astronomy, religion and philosophy that crystallized the elements of what is generally known as Hindu culture. The decimal numeral system, including the concept of zero, was invented in India during this period. The peace and prosperity created under Guptas leadership enabled the pursuit of scientific and artistic endeavors in India.