The Nicomedia mint reopenned after Anastasius' reform of 498 to assist in issuing the new denominations of copper coinage and closed in 627. Situated on the roads leading to the capital, Nicomedia was a major military base, important in the Byzantine campaigns against the Caliphate. By the 9th century much of the city, except for a hilltop citadel, was abandoned and in ruins. Nicomedia was twice blockaded by the Ottomans (in 1304 and 1330) before finally succumbing in 1337.