Mount Everest is the highest peak from sea level at just over 29,000 ft. It sits on the border between Nepal and Tibet/China.
The highest mountain on earth is actually Mauna Kea in Hawaii. This volcano measures 33,000 ft from its base of which just over 13,000 feet are above the surface of the ocean.
If I could add....Tibet will always be a country in the minds of Tibetans and others regardless of the power of China.