So it finally happened. After years of ignoring God and not paying due tribute to Babylon as the local superpower, Judah got to see the fulfillment of prophecies from Jeremiah, Ezekiel, Isaiah, and many others.
Historians tell us the siege began in 588 BC. There was a short break, but overall it lasted for two and a half years:
2 Kings 25:1–2 So on January 15, during the ninth year of Zedekiah’s reign, King Nebuchadnezzar of Babylon led his entire army against Jerusalem. They surrounded the city and built siege ramps against its walls. Jerusalem was kept under siege until the eleventh year of King Zedekiah’s reign.
That Bible blog 