For example, in Divrei Hayamim Beth 36:4, the king of Egypt crowned Eliakim over Judah and Jerusalem, and he changed his name to Jehoiakim. In Melachim Beth 24:17 the king of Babylonia crowned Mattaniah, and changed his name to Zedekiah. In the book of Daniel, the chief officer of Nebuchadnezzar changed the name of Daniel to Belteshazzar, Hananiah to Shadrach, Mishael to Meshach, and Azariah to Abed-nego. Why did they change their names? Did they try to change their Jewish identity? Was there anything in these names that was incompatible with their religions? Or they just wanted to impose their power?
Da'at Mikrah write in their introduction to the Book of Jeremiah:
"...Instead of him [=King Yehoachaz], appointed Nekho Eliakim ben Yoshiyahu, who agreed, it seems, to be subject to Egypt, and even changed his name of Eliakim to the name Yehoyakim (most likely, as if to tell him, that he rules by the benevolence of the king of Egypt). [...] Instead of Yehoyachin, placed Nevuchadretzar Matnaya, third son of Yoshiyahu, upon the throne, and changed his name to Tzidkiyahu, the same way that Pharaoh Nekho changed the name of Eliakim to Yehoyakim, probably from the same reason, to show the world that Tzidkiyahu isn't but a servant of Babylon."
It seems, therefore, that the name-change stemmed from want of imposing power, in particular considering that those were very restless times in the Middle East, filled with wars and rebellions.