Rafael Lapesa was a man who lived a long time ago and he did lots of important things with language. In particular, he studied the Spanish language very carefully and wrote books to help other people understand it better.
He spent many years researching and studying the history of the Spanish language, and he wrote a big book all about it called "Historia de la Lengua Española" (which means "History of the Spanish Language" in English). He also wrote other books that helped people learn about Spanish grammar, pronunciation, and vocabulary.
Overall, Rafael Lapesa was a very smart man who did lots of important work to help people understand and appreciate the Spanish language.