The Ottomans' first strategic goal was to capture the Tower of St Nicholas, which was the knights' key point in the defence of the two harbours: Mandraki, and the one to the east bay of Akandia. The Turkish artillery kept up an unbroken bombardment and from 9 June on the infantry made a series of attacks. Grand Master d'Aubusson himself sped to the aid of the garrison and after a fierce struggle the enemy was repelled.