Disambiguations of Rishonim

Often times, two contradictory statements of a Rishon will baffle the Poskim, and all it takes is a little history to know that there were actually two or more people with the same name, each of which said one of the contradictory statements.

Raavad

1. It's important to be aware that there are three individuals known as the Ra'avad: R' Avraham ibn Daud of Spain, author of Sefer HaKabbalah; R' Avraham ben Yitzchak Av Beit Din of Narbonne, who wrote the Sefer HaEshkol; his son in law, and R' Avraham ben David of Posquières, author of the Hasagot on the Baal HaMaor and Rambam, Baalei HaNefesh, and quoted extensively by Rishonim.

Rabbeinu Yonah

1. There were at least four Rabbeinu Yonahs:
   1. R' Yonah Gerondi (HeChassid), whom we know as Rabbeinu Yonah, cousin of the Ramban, and Rebbe of the Rashba. His grandson, son of his daughter and the Ramban's son Shlomo, was named R' Yonah after him. He had grandson who was also named R' Yonah, whose daughter married the Rashbetz and was thereby the grandfather of the Rashbash.
   2. R' Yonah שניין, a relative of the latter, who overlapped in his lifetime.
   3. R' Yonah author of the Sefer Issur veHetter and Talmid of the Terumat HaDeshen. Printers and Poskim mistakenly labeled his Sefer as a product of R' Yonah Gerondi, but it's clearly impossible.

Rabbeinu Baruch

1. Sefer HaTerumah was written by R' Baruch MiRegensburg, the student of R' Eliezer MiMitz, R' Baruch MiMagence, who wrote Sefer HaChochmah.

Rabbeinu Zerachia

1. There were two R' Zerachiahs, one of whom was the Baal HaMaor.

Ri

1. There were two Ri Baalei HaTosafots, one of whom was the Ri HaZaken, nephew of Rabbeinu Tam.