Where does “ইস্তাম্বুল” come from?

ইস্তাম্বুল (Bengali) comes from English Istanbul, from Turkish İstanbul, from Byzantine Greek πόλις, from Proto-Hellenic ptólis, from Proto-Indo-European tpólHis, from Proto-Indo-European tpelH- — fortification, city.

Ancestry of “ইস্তাম্বুল”, step by step

StepLanguageWordMeaning
1EnglishIstanbulA Turkish city, and the largest European city by population, which was the last capital of the Ottoman Empire and the Byzantine Empire (Eastern Roman Empire)
2TurkishİstanbulIstanbul
3Byzantine Greekπόλιςin the City; city; a whole country, as dependent...
4Proto-Hellenicptóliscity
5Proto-Indo-EuropeantpólHis
6Proto-Indo-EuropeantpelH-fortification, city
Every word from Proto-Indo-European tpelH-Every word from Proto-Indo-European tpólHisEvery word from Proto-Hellenic ptólis