Yapu is a city of the country of Upi, mentioned four times in the Amarna letters. The most illuminating is the EA138 letter from the mayor of Byblos, Rib-Addi, which responds to a request from Pharaoh to visit Yapu. Rib-Addi replied that he did not go to the country of Upi due to the instability of the region.
There is striking similarity between the name of the city and that of the region. No doubt that the second comes from an older pronunciation of the first.
Historians agree to consider that this city, called Yapu in Akkadian cuneiform, is the current Jaffa, on the coast of the Levant, whose oldest part is called "Tell Yaffa."
J Kaplan, in 1956, finds Byzantine archaeological layers, Hellenic, Persian, then the Iron Age and three layers of the Bronze Age. Excavations are ongoing.
Egyptologists are agreed, this city is mentioned in a story of "The taking of Joppa," which tells that the general Djéhouty conquered this town by a similar subterfuge to Trojan: two hundred Egyptian fighters hid in baskets given as gifts to the governor of the city.
An inscription of Sennacherib, made between 705 and 681 BC, mentions Yapu. The Hellenistic tradition gives the name of "Iopeia".
It is appropriate to distinguish between Yapu, which is the city of Jaffa of the country of Upi and Ipu, place of worship of Min in Middle Egypt.
On the pylons of Karnak which list the towns under Egyptian rule at the time of Thutmose III is a city of Ipu: there, Egyptologists agree to consider it the Jaffa city. And so we are in the presence of two homonymous cities.
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My notes of veracity :
Yapu is the Akkadian old name of the current city of Jaffa: 4/5
Ipu is the Egyptian old name of the current city of Jaffa: 4/5