Philippine-based militants led by Isnilon Hapilon are continuing their efforts to build an Islamic State presence in Central Mindanao. The Battle for Marawi has demonstrated how conflict-affected areas, specifically in the Lanao del Sur province, are favourable to the entry of foreign jihadists. These individuals may decide to join IS-affiliated groups in the Philippines instead of travelling to the Middle East. As the IS core faces increasing pressure from coalition forces, Mindanao could serve as a halfway house for Katibah Nusantara fighters seeking to hone their combat skills before returning to their countries of origin. Denying space to a potential ‘wilayah Mindanao’ rests on the success of the peace process with mainstream Filipino Muslim groups.