The sultans (emperors) of Delhi enjoyed cordial relations with rulers in the Near East but owed them no allegiance. While the sultans ruled from urban centres, their military camps and trading posts provided the nuclei for many towns that sprang up in the countryside. Close interaction with local populations led to cultural exchange and the resulting "Indo-Islamic" fusion has left a lasting imprint and legacy in South Asian architecture, music, literature, life style and religious customs. In addition, the language of Urdu (literally meaning "horde" or "camp" in various Turkic dialects, but more likely "city" in the South Asian context) was born during the Delhi Sultanate period, as a result of the mingling of speakers of native Prakrits, Persian, Turkish and Arabic languages.