What was the highest mountain in the world before discovering Mount Everest?
There are three highest mountains. Everest is the highest above sea level. Mauna Kea is the highest above its base. Chimborazo in Ecuador is the highest above the center of the Earth. You never heard of Chimborazo because anybody can climb it. It is a popular picnic site.
Before they were discovered they were still the highest mountains on the planet.