The big guns opened up on 6 May...soon another portion of wall fell in. At about 7 o'clock at night, with the customary din, a massive assault was launched at the breach. Thousands of men crossed the ditch and ran for the breach...Guistiniani rushed to meet the intruders and a desperate hand-to-hand struggle took place in the gap.
In the first wave, a Janissary called Murat led the assault, slashing fiercely at Guistiniani, who was only saved from death by a Greek jumping down from the wall and cutting off his assailant's legs with an axe. A second wave was led by one Omar Bey, the standard bearer of the European army - and was met by a substantial contingent of Greeks commanded by their officer Rhangabes. In the slashing, hacking confusion, the two leaders squared up to each other in single combat in front of their men. Omar 'bared his sword, he attacked him and with fury they did slash at each other. Rhangabes stepped on a rock, grasped his sword with two hands, struck him on the shoulder, and cut him into two, for he had great strength in his arms.' Infuriated at the death of their commander, the Ottoman troops encircled Rhangabes and cut him down. Like a scene from the Iliad, the two sides surged forward to try to seize the body. The Greeks were desperate to gain control of the corpse and piled out of the gates, 'but they were unable and suffered many losses.' The Ottomans cut the mutilated body in pieces and drove the Greek soldiers back into the city. For three hours the battle raged on but the defenders successfully held the line. As the fighting died down, the cannon started to open up again to prevent the breach being filled and the Ottomans launched a second diversionary raid, trying to set fire to the gate near the palace. This was again defeated. In the darkness Guistiniani and the exhausted defenders worked to rebuild the makeshift defences. Because of the firing at the wall, they were forced to build their protective barrier of earth and timber slightly inside its original line. The wall was holding - but only just. And inside the city 'there was great mourning and dread among the Greeks over Rhangabes, because he was a great warrior, was courageous, and was beloved of the Emperor.'
- Constantinople: The Last Great Siege, Roger Crowley