Hosea was a contemporary of Amos in Israel, and of Isaiah and Micah in Judah, and his ministry continued after the first, or Assyrian, captivity of the northern kingdom 2 Kings 15:29 . His style is abrupt, metaphorical, and figurative.
Israel is Jehovah's adulterous wife, repudiated, but ultimately to be purified and restored. This is Hosea's distinctive message, which may be summed up in his two words, Lo-ammi, "not my people," and Ammi, "my people." Israel is not merely apostate and sinful--that is said also; but her sin takes its character from the exalted relationship into which she has been brought.
The book is in three parts:
The events recorded in Hosea cover a period of 60 years (Ussher)