The proper name given by the Pope to describe the ethnic Assyrians who split from the Assyrian Church Of the East to the Roman Catholic Church known as the Great Schism. They speak a dialect of Chaldean Neo-Aramaic. For four centuries the Catholic Church tried to convert the Assyrians to Catholicism. It must be mentioned that the Assyrians of different religious denominations (Orthodoxy, Nestorian, Catholic, Maronite etc.), due to their lack of education, are not united as one nation but hate each other, thinking the others are foreigners!
The King of Assyria; Essarhadon, had 2 sons named Ashurbanipal (who had already been in control of Nineveh to the North) and Shamash-shum-ukin (The Predecessor of KALDU). After King Essarhadon's death, Babylonia was left to be governed by his son Shamash-shum-ukin and eventually revolted against his brother in 652 BC. In 626 Bc, Babylon had eventually threw off the Assyrian rule under King Nabopolassar's reign thus creating the Neo-Babylonian Empire (Chaldean Empire) with Babylon as the capital.