Easton's Bible Dictionary
This name Israel is sometimes used emphatically for the true Israel (Psalm 73:1 : Isaiah 45:17; 49:3; John 1:47; Romans 9:6; 11:26 ).
After the death of Saul the ten tribes arrogated to themselves this name, as if they were the whole nation (2 Samuel 2:9,10,17,28; 3:10,17; 19:40-43 ), and the kings of the ten tribes were called "kings of Israel," while the kings of the two tribes were called "kings of Judah."
After the Exile the name Israel was assumed as designating the entire nation.
These dictionary topics are from M.G. Easton M.A., D.D., Illustrated Bible Dictionary, Third Edition, published by Thomas Nelson, 1897. Public Domain.
Easton, Matthew George. Entry for 'Israel'. Easton's Bible Dictionary. https://www.studylight.org/dictionaries/eng/ebd/i/israel.html. 1897.