Portuguese sixteenth-century sources provide much information on the countries neighbouring the Portuguese positions in India, chiefly Goa. There are many interesting elements especially on the Sultanate of Bijapur, a little less on that of Ahmadnagar, and only disperse notes on the other sultanates of Deccan, which had scarce relations with the Portuguese. They bear witness to the presence of many Iranians, in the armed forces of the sultanates as well as in their civil administration. Some Portuguese chroniclers were quite sensitive to social cleavages and balance of forces, whilst others only note anecdotic aspects. Even so, they furnish the names of many individuals, and something on their lives, which often complete those provided by the Indo-Persian writers; provided they are compared with the latter, they can be used by researchers with good results. The article also tries to explain why Iranians were more numerous and more influential in the Deccan than in other parts of Moslem India, such as Gujarat. It will be followed by a second one dealing with Iranians in maritime India and around the Indian Ocean.