The custom of dressing up in costumes on Purim originated from Ashkenazic communities in Europe and has become a popular custom today for Ashkenazim (cf. Rema in Shulkhan Aruch Orach Chaim 696:8). ...
Who was the Author of the Piyut "asher hanee" that ends with Shoshanat Yaakov? Why is it said by Ashkenazim after they read the Meggilah at night?