The Ritva, Rabbi Yom Tov ibn Asevilli, was the rabbi and head of the Yeshiva of Seville in Spain. Neither the exact year of his birth nor of his death is known, but a good approximation is that he was born in the 2nd half of the 13th century and that he was niftar in the 1st half of the 14th century. It is known that he and his Yeshiva flourished around the year 1320.
He was the leading student of the Rashba and of the Raah and was a talmid muvhak, a student very closely attached to the latter.
His commentary on the Talmud is known for its clarity of thought and of expression, and it is in very wide use throughout the Torah-learning world.
Many sheelot, questions regarding Jewish Law, were sent to him, even during the lifetimes of his great teachers. This shows that he was considered in his maturity by the Jewish world to be in the same league as they were; that is, he was on a similar level of Torah knowledge and ability to use that knowledge insightfully to apply it to questions that arose in his day.
Despite his high standing in the eyes of the Jewish community and even in the eyes of the Spanish royalty and the Catholic Church, it is clear from his writings that he remained humble.
In the Golden Age of Spanish Jewry, he was one of the leading lights of the Jewish People.
Sources: Orthodox Union