A Persian proverb says "The problem of this fountain is from the fountainhead", it comes from this famous Persian poem of  Sultan Suleiman the Magnificent, the greatest Ottoman sultan:

Dideh az atash del gharghe dar ab ast mara
Kar in chesmeh ze sar chemeh kharab ast mara

(From the fire of the heart, my eye has been drowned in the water
The problem of this fountain is from the fountainhead)

Unfortunately in the eye of Europeans Turks have been always an uncivilised people even after hundreds years ruling the greatest empires of the world, it is really an insult to say that the compatriots of Rumi who his Greek poems are being compared to poems of great Greek poets, couldn't undrestand the meaning of the Greek phrase of "cis tin Polin" and thought this is the name of the city, the more interesting thing is that it is said Turks even couldn't pronounce this phrase correctly, so they changed it to Istanbul!! Sorry this is nothing more than a joke!

Where is the Eurasian Land Bridge?

As I mentioned several times Istanbul is a very Persian word which means exactly "Land Bridge", I hope you at least know that Afghanistan means "Land of Afghans" and its capital Kabul means "Mountain Bridge".

Polis means city in the Greek language, Persians and Turks also usually referred to their great cities "Istana/Astana" which also means "City/Capital" in the Persian language (the new capital of Kazakistan is also called "Astana"), for a long time Istanbul was the most famous city which was called "Astana".

6, Astanih [Istanbul]:

Astanih (vol 1, p 177), is the same Islambul, capital of Osmani (Ottoman), in the old times it was known as Astanih.

http://www.hizb-ut-tahrir.org/english/books/howthekwasdestroyed/chapter_04.html - The role of the Istanbul Centre in working towards hitting the Khilafah State

A question on a slightly related note, if you guys will indulge my ignorance. Does anyone know whether or not "Izmir" is a corruption of "Smyrna"? And if not, how did it come by its name?

"The name İstanbul comes from the http://en.wikipedia.org/wiki/Greek_language - Greek words εις την Πόλη – eis tēn Pólē (pronounced [is tim boli]) or στην Πόλη, from http://en.wikipedia.org/wiki/Ancient_Greek - Ancient Greek eìs tēn Polin (εἰς τήν Πόλιν) and meaning "in the city" or "to the city". ^{http://en.wikipedia.org/wiki/Names_of_Istanbul#_note-0 - [2]} Similar examples of modern Turkish town names derived from Greek are http://en.wikipedia.org/wiki/%C4%B0zmit - İzmit (from İznikmit which was Nicomedia and http://en.wikipedia.org/wiki/%C4%B0znik - İznik (from Greek, Nicaea: "eis tin Nikaia" (pron. [is tin nikea]), becoming [znik].

The intermediate form "Stamboul" was commonly used by the Turks in the 19th century. Because of the custom of affixing an i before certain words that start with two consonants (as in "İzmir" from Smyrna: in a coincidence of s + m, the s turns to z in pronunciation, as has been attested since early Byzantine times and in modern Greek usage), it was pronounced in Turkish as İstambul. (The /m/ in the middle is also an example of http://en.wikipedia.org/wiki/Assimilation_%28linguistics%29 - linguistic assimilation , whereby the /n/ becomes an /m/ before a /p/ or /b/, as in çenber → çember, anbar → ambar; such rules are not, however, always observed in proper nouns like Istanbul. A similar change occurs in Greek, where an /n/ before a /p/ becomes an [m], and the /p/ after /n/ becomes a b in pronunciation .)

This theory that "Istanbul" came from "Eis tin Polin" is a joke? This was how everyone in Constantinople called the city and it was such a usual sound in the ears of Turks that named the city Istanbul (which is a corruption). That's what first came to the turkish mind when the Turks conquerred Constantinople regarding the name of the city. Constantinopolitans Greeks know it very well from the coexistence with the Turks in Istanbul. All the other explanations are nothing more than constructed theories to cut off even the new name of this city from its greek origin.

I have a question to ask...

If this "Cyrus theory" or the "theory of an iranian friend" (that's how the Turks in this thread call it) is correct, I wonder why Turks don't know it? Most of the Turks I have talked with about this subject don't know this theory and the few who know it, told me that they learned it recently.

If I was a Turk and the name of this city meant something in my language I wouldn't expect from Cyrus or anyone else to explain it to me. 

Name of city is persian, so It does not mean  anything at turkish langauge.

You should know the history of its name better then.

Cyrus,

Nice try!

The eastern world (Arabs, Persians) knew this name from the contact with the Byzantines that's how Turks learned it too before the conquest.

First of all what we need to understand is that Ancient Hellens used Hellenified versions of foreign toponyms,cities,names,sometimes totally different ,sometimes not.For example ,the name Darios for the Persian dara.The Hellenic word Hettaios,or in english Hittite, for the Hebrew Heth.

 During the period of the Old kingdom  ,the Hittites were mainly focusing their military operations in   Northern Mesopotamia due to existence of significantly powerfull enemies such as the Hurrites ,and the Giamads in Syria.There were Hittitian colonies in Syria and maybe in Palestine ,but not in Western Asia Minor.If again we accept the fact that Troy was located near the Straits of Hellispontos,the only organized State west of Hattusa and of the Hittitian State was the kingdom of Troy,as described in the Homer's Illiad and Odyssey.The only shore that the Hittites reached was the Southern,an area where Hellens did not found any colonies,with the domination over Arzava.During the New Kingdom,a period of political instability and foreing invasions ,the only serious Western threat was from Arzava,which was in the mainland of Asia Minor.The whole epicenter of politics and strategic campaings was the area of Syria,Northren Mesopotamia and Taurus mountains,due to the fact that all possible enemies were in that specific area ,such as the Egyptians ,the Assyrians,the Mitanni etc.The Ahigiava ,a Western power mentioned in scripts since the reign of Supiluliumas (1375 B.C),were in the fact the Ahaioi ,Hellens from the Hellenic mainland who had founded colonies in the Western shore of Asia Minor.So,we see Hittitian presence in the Southern  shore of Asia Minor,e.g the city of Tarsa(later Tarsos) and no Ahigiavan colonies,colonies of the Ahaioi while there were no major cities in the Western shores,where the Ahigiavan presence,again the presence of the Ahaioi, was strong.

Before the Hittites,the Luvians had under their influence and control the area from Kizuvatna in the East (North of Tarsos) to Luka and a part of  Karia in the West.But still,they had not reach the shores of Western Asia Minor.

The Phrygians were the only ones from the people of the "Aegean Immigration",which "officialy" ended the rule of the Hittites in the region, who managed to found a form of State.The Phrygian State had as it's Western border the river Maiandrus,not the shores of Western Asia Minor.The only ones that managed to really reach the shores were the Lydians.But the Hellenic presence in the area had already been known and later established since the Ahigiava.In fact some of the colonies were founded in the last years of the Mycenean Era.

So the only Western State which ruled in the shores,was the kingdom of Troy ,which was destroyed by the Ahaioi(Ahigiava).

As for the names,the Hellens ,as mentioned above ,used Hellenified versions for foreign names ,e.g Lykia for the Luka,Asia for the Asuva.The name Ahigiava could actually come from the Hellenic Ahaioi and not the other way around.And that's all.

1) the city were there ages before persian or seltzuk or romans came there. Was a Greek colony. City's first name was Byzantium. Later the romans (wich culture was completely Greek) after their conquer the entire region decides that that city was the perfect spot for their new capital. So The emperor Konstantinos make a new citi next to Bizantium and called her Constantinoupoli. Later when Ottomans conquer the Byzantium (Actually whats left from the crusaders the City and some parts of Greece) they changed citis name. And is called Istanbul.