The Minor Prophets
The Minor Prophets — or The Twelve as they are called in the Vulgate, the Hebrew Bible and the Septuagint — were so called because of their brevity rather than because their ministries were less important.
The books of the twelve prophets span about four and a half centuries - dating from the ninth century before Christ to the fifth century before Christ - and cover three significant periods of Israel's history.
The Assyrian Period (Hosea to Nahum)
The Babylonian Period (Habakkuk and Zephaniah)
The Persian Period (Haggai, Zechariah, Malachi)
These are the Minor Prophets.