This high culture approach to television could be interpreted as a product of its time as networks were concerned with "cultural uplift" and viewed it as a way to cultural legitimacy on the new medium. A similar uplift occurred in the late 1990s - early 2000s, when the networks were switching to high definition format. This was the time when Discovery Channel commissioned Discovery HD Theater to broadcast HD documentaries about nature and history, while BBC released Planet Earth. This coincided with the rise of the new Golden Age of Television that arose in the 21st century.