On 13 April 1920, the first conflict occurred at Düzce as a direct consequence of the sheik ul-Islam's "fatwa". On 18 April 1920, the Düzce conflict was extended to Bolu; on 20 April 1920, it extended to Gerede. The movement engulfed northwestern Anatolia for about a month. The Ottoman government had accorded semi-official status to the "Kuva-i Inzibatiye" and Ahmet Anzavur held an important role in the uprising. Both sides faced each other in a pitched battle near Izmit on 14 June. Ahmet Anzavur's forces and British units outnumbered the militias. Yet under heavy attack some of the Kuva-i Inzibatiye deserted and joined the opposing ranks. This revealed the Sultan did not have the unwavering support of his men. Meanwhile, the rest of these forces withdrew behind the British lines which held their position.