'House of Israel' in the Bible

Now when Rehoboam arrived in Jerusalem, he assembled all the [fighting men from the] house of Judah, with the tribe of Benjamin, 180,000 chosen warriors, to fight against the house of Israel to bring the kingdom back to Rehoboam the son of Solomon.

But his servants said to him, “We have heard that the kings of the house (royal line) of Israel are merciful kings. Please let us put sackcloth around our loins and ropes on our necks [as symbols of submission], and go out to the king of Israel; perhaps he will spare your life.”