The walls themselves were actually breached at a similar time to the door being left open. The cannons had done a reasonable job at damaging the walls but the defenders were able to repair it, the problem was that they could only repair it in a haphazard way; skins, barrels, wood etc and it was at one of these points that a segment of the wall actually gave way allowing Mehmed to chuck everything he had at it. The defenders may have been able to stop it but obviously the enemy were already behind by this point.
I'm aware of this. I'd contend, however, that had the gate not been opened the Byzantines would have been able to shore up the wall.
Crucially it is allegedly damage from cannon fire which led to injuries to Giustiniani, the de facto leader of the troops on the wall, which led to numerous Genoese already there leaving the walls to protect him back on the ship.
This is a far bigger deal than yet another breach in the wall. Giustiani was possibly the greatest proponent of defensive seigecraft then living. His loss was a tremendous blow.
This book is quite an interesting overview of the final period;
http://www.amazon.co.uk/Constantinople-Last-Great-Siege-1453/dp/0571221866
I think that was the book which began me on my dissertation trail.
I read it a while back. Been a while though.
But i'm not sure that the Venetians would have suddenly decided to come and help out, if the siege had failed it would have been just another countless siege which failed on Constantinoples walls and therefore why would it have made any difference to them.
The deal with Venice at the time was that there was a split amongst the elite. There were two factions, one of which wanted to send aid and one of which wished to withhold it. As it was, neither side gained supremacy; they were still arguing it out when the city fell. If Constantinople had survived the seige, there is a decent chance that the pro-intervention faction would have gained power and broken the blockade. Of course, there's also a good chance that the two sides would have continued to argue rather than reach any concrete decisions one way or another, but I don't see the Ottomans remaining a threat long enough to maintain the blockade more than another year anyway.
@ Lord Baal
Wait, didn't Mehmed ordered that all cannons to fire upon a weak spot in the wall which eventually was breached terribly?
Yes. It didn't matter; the defenders could rebuild the walls quicker than the Turks could destroy them, even if the new "walls" were little more than piled-up rubble. Regarding the accuracy of the cannons; they weren't terribly accurate. They were, on the other hand, very large, so they didn't have to be that accurate. If they all hit near-enough to the same section of wall, they'd bring it down.
I am certain that the combination of the Ottomans breaking down parts of the wall, the unlocked gate and the pressure on the sea-side walls and with the psychological blow of the withdrawal of the Genoese in the final assault caused the city to fall.
It was the open gate that caused the city to fall. The other factors were certainly problematic - the blockade is as likely to have kept Constantine XI from leaving as any thoughts of noble sacrifice - but the breach in the wall was the final straw.
I knew that it was imperative that Mehmed capture the city in the next two months, not because they were running low on supplies but because the Christian Powers were planning to relieve the city in a crusade.
There was no crusade. The Pope and Constantine were both hoping for one, but it wasn't coming. At most, a few mercenaries and maybe the Venetians would have shown up to help the city, but that's all.
Also, the siege of the city via the sea-side walls put immense pressure on the Christians as they now had to defend two walls instead of one.
What is this second defense that you speak off? I thought Constantine had only enough money and time to repair the outer most wall? The second wall and moat wasn't had no upkeep.
Constantinople actually had three walls. The outermost wall was the most important of the three, but all three were capable of holding off an assault to some extent. I'm referring more to Constantine's private keep and some inner barricades than the second and third wall though.
In my view, the city was doomed to fall. Even if the gate was not left open, the walls were beginning to take serious damage and that Byzantine/Italian casualties were starting to become too serious to properly defend the walls for more than a few weeks. The open gate was a matter of time.
I concede that the casualties were mounting on the side of the defenders. I do not believe, however, that those casualties would have doomed the city before the Ottomans were themselves forced to withdraw.
Actually the feared Crusade wasn't actually going to happen. Mehmed thought that the Hungarians, Venetians and others would march to relieve Constantinople, but if I recall my reading correctly at the time neither had much interest in doing so and the Ventians made only a haphazard lackluster attempt to send aid. The Ottomans had built forts along the Dardanelles particularly Rumeli Hisari (the Throathcutter) which would have complicated any serious attempt by the Ventians to relieve Constatinople. In fact Constantine IX offered the Ventiains, Genoese, and Hungarians all pieces of the territory he had left, I believed he offered the Ventians some trading rights and a few of the islands he had left, and possibly the Morea I think he offered the Hungarians the island of Marama and something else, but none of them went for it.
The fear of a crusading army showing up did have an effect on the thinking of Mehmet and his generals though, there can be no doubt of that. Constantine XI knew it wasn't coming, but the opposition didn't.
Also the Byzantines wanted to hire Orban
I am utterly humiliated by how badly I misspelt this chap's name.
(who was a Hungarian) and he was in their service for a few months at least and offered them both cannons and arqubuses, but he left Constantinople after the Emperor failed to pay him several times. The Byzantines were bankrupt, they had no money, they couldn't afford Orban's services.
Don't forget that even had they possessed the funds, the Byzantines had no intentions of paying for some of Orban's ridiculously over-sized and useless weapons. Some of Mehmet's generals also advised against it.
So he jumped ship and went to Mehmed who paid him lavishly and ordered the construction of a massive cannon. The cannon worked and I believe was even instrumental in reducing Constantinople.
The cannon was great... Once. The problem was that it was so goddamn big it took several hours to reload. Not only that, but the recoil routinely destroyed the wooden base for the cannon, requiring the construction of a new one every time.
In modern day Istanbul there is even a street named after Orban, which is the location where he presumably resided and remained in the service of the Ottoman Empire.
Orban is a pretty mysterious character. Other than that he was Hungarian, worked for both sides, and supposedly stayed in the service of the Sultan after the Fall of Constantinople, next to nothing is known about the guy.
