On Wednesday, Syrian rebels shocked the world with a surprise offensive against President Bashar al-Assad's forces in northern Syria. In a swift operation lasting under 72 hours, they seized significant portions of Aleppo, the nation’s second-largest city, which had taken regime forces over four years to reclaim.

Employing tactics painfully familiar to Israelis - rocket assaults, drone strikes, and rapid incursions from concealed positions—the rebels managed to outmaneuver the Russian and Syrian air forces that dominate the skies. The attack was a remarkable success, catching the Syrian army and its allies, including Iranian militias and Russian troops, off guard. Footage of the rebels celebrating their triumph, capturing prisoners, seizing abandoned weapons, and chanting religious slogans circulated widely.

But who are these rebels, and how did they emerge after years of the Syrian conflict fading from view? The answer is intricate, reflecting the complex political landscape of the uprising. Broadly, the rebel forces can be categorized into two main factions.