To which land were the people of the northern kingdom of Israel exiled?

Answer: Assyria

When Samaria fell, the Israelites were carried to Assyria and settled in Halah, in Gozan by the Habor River, and in the cities of the Medes.

“In the ninth year of Hoshea, the king of Assyria captured Samaria and carried away the Israelites to Assyria, where he settled them in Halah, in Gozan by the Habor River, and in the cities of the Medes.”— 2 Kings 17:6 (BSB)