Hosea, an 8^th century Prophet like Jonah and Amos, prophesied to Northern Israel, named after the largest of the 10 tribes there (Ephraim).
At the same time, Isaiah and Micah were prophets to Southern Israel (Judah).
Hosea’s ministry, was about (755 -710 BC), overlapping the reign of King Jeroboam II (793-753 BC), Hosea 1:1.
Hosea’s ministry, began near the end of Jeroboam II’s reign, of N. Israel (793-753 BC).
His ministry also overlapped the S. Israel (Judah) reigns of Uzziah (Azariah), (790-739 BC), Jotham (750-732 BC), Ahaz (735-715 BC), and Hezekiah’s (715-686 BC).    

King Jeroboam II, was an Evil King, 2 Kings 14:23-29, Hosea 1:1           
His reign was marked by great economic and political success but growing spiritual apostasy.

In 732 BC Damascus had fallen to the Assyrians  and by 722 BC Samaria, the capital City of N. Israel, fell to the Assyrians and N. Israel went into Exile (2 Kings 17:6).
This was the fulfillment of prophecy by Hosea (Hosea 8:9-10, 9:3, 11:5)

Hosea wrote before the Exile of Northern Kingdom of Israel: (722 BC), 2 Kings 17:1-6
and before the Exile of Southern Kingdom Judah (605, 597,586 BC), 2 Kings 24:1, 24:8-16, 25:1-30