Yitzchak Myer Alter (also Rottenburg, Rothenburg or Rothenberg as an alternate for "Alter") (1798 – 10 March 1866), is considered to be the first Rebbe of the Ger Hasidic dynasty, which he founded in the town of Góra Kalwaria (known as "Ger" in Yiddish), Poland. He was also known as the Chidushei HaRim for his Torah books. He is sometimes referred to fondly as Reb Itche Myer by his followers.