What are some big historical figures and national heroes from your country that aren't well-known abroad?

Santos Dumont is hailed here in Brazil for being a major pioneer in airflight, making the biggest early showcase of a self-propelled airplane in Paris in the early XX-century. We have many places named after him, including a major airport in our former capital Rio de Janeiro. Still, in the international stage, he usually gets overdhadowed by the Wright Brothers in how the creation of the airplane is told.

Is there any case like this for your country? Someone who is a hero or very important national figure in your country, but few people in other countries know about them?