God called the prophet Jonah to go and preach against Nineveh, the great city, and Jonah ran the other way (Jonah 1:1). After the storm and the great fish, God called him a second time, and this time he went. His message was short: in forty days the city would be overthrown. To his dismay, the people believed God; from the king down they fasted, put on sackcloth and turned from their violence, and God relented (Jonah 3:5).
Jonah was angry, and the book ends with God's own question to him about caring for a city full of people and animals who did not know right from left.
“But the LORD said, “You cared about the plant, which you neither tended nor made grow. It sprang up in a night and perished in a night.”
Nineveh's repentance did not last. Assyria destroyed the northern kingdom of Israel in 722 BC, and in 701 BC Sennacherib invaded Judah, captured Lachish and threatened Jerusalem. Hezekiah prayed, the city was spared, and Sennacherib went home to Nineveh, where he was later killed by his own sons while worshiping his god (2 Kings 19:35).
About a century after Jonah, the prophet Nahum announced Nineveh's end. He described the Lord as slow to anger yet just (Nahum 1:3), and pictured the river gates thrown open and the palace collapsing (Nahum 2:6). Zephaniah foresaw the proud city turned into a dry pasture for flocks (Zephaniah 2:13). In 612 BC an alliance of Babylonians and Medes sacked Nineveh, and it never rose again.
Jesus himself pointed back to the city. The people of Nineveh, he said, repented at Jonah's preaching, and now someone greater than Jonah was here (Matthew 12:41, Luke 11:30).