Benedict Arnold. Rarely has an officer of his level turned traitor.
Bill Halsey deserves a nomination at least just so we can enjoy the debate.
General John A McClernand was a useless political hack that hurt the Union’s efforts.
I see willthekittensurvive? beat me to Lopez. Still thinking of others…
I don’t get the reference, I’m afraid. Explain?
ANY pre-Grant Union commander qualifies.
Even though I nominated him in the “best military leader” thread, he seems worthy of a mention here:
Douglas MacArthur – Dismissed from Korea by Truman
Still thinking about my other nominations.
Nicias - commander of the Syracuse expedition
at 2.20 Karremans says “I always say I am the piano player…. Don’t shoot the piano player”
Abdel Hakim Amer - panicked, lost Sinai in 1967.
Pyrrhus of Epirus - invented new way of losing.
Daniel Sickles - almost lost Gettysburg single-handedly.*
James II of England - surrendered Britain without a fight.
*Or should I say single-leggedly?
So victory in battle makes one “worst” ? 
'course, I could be predjudiced, they are from Ohio;)
Remember, the thread is not “worst person who happened to be a military leader”. Ghengis Khan killed a lot more civilians than Sherman did.
I realize it’s like asking gringos to write Hernán Cortés’ name with an s, but as General Santa Ana spelled the saint’s name with a single n, it might behoove this site to do it as he did it. “Santa Ana”, please.
Final pick: Philip VI of France, crushed own army at Crécy.
The first page of every Google result lists him as “Santa Anna,” including the Wikipedia entry, a PBS story, and U. of Texas and TAMU profiles.
A fair point - but on the other hand, this is an Anglophone board. Doesn’t seem unreasonable to employ spellings commonly used in the Anglophone world.
Admiral Sir Cloudesley Shovell, who wrecked his fleet on the Scilly Isles: “one of the greatest maritime disasters in the history of the British Isles.” (Also nominated as military leader with silliest name, and scilliest location for his military disaster.)
List of nominees so far (in the order they were nominated - I’ll leave it to Elendil to alphabetize and cut things to 5 words). I think I got all the disqualifications and duplicates, but might have missed something:
Horatio Gates: Fled headlong from Camden, S.C.
James Ledlie: Drunk during Battle of Crater
Braxton Bragg: Bungling, irritating Confederate general
Heinrich Himmler: Nazi botched every field command
Christian de Castries: Lost at Dien Bien Phu
James Brudenell, 7th Earl of Cardigan: Charge of the Light Brigade.
Arthur Percival, surrendered Singapore to Japan
Publius Quinctilius Varus, army totally annihilated in Germany
Lieutenant-Colonel Thom Karremans: Toasted Mladić, allowed Srebenica massacre.
2nd Lt. William Calley: Ordered, led My Lai Massacre.
**Ratko Mladić **: Ordered Srebenica massacre, convicted scum.
General William Tecumseh Sherman: Arsonist, War Criminal.
George Armstrong Custer: Idiot.
Ulysses S. Grant: Butcher
Benjamin Franklin Butler: Beast.
William Westmoreland: Brutal, unimaginative technocrat
Paul D. Harkins: Ignorant and overoptimistic, allowed Vietnam to escalate
Maximilian von Prittwitz: Peed his pants in Prussia (alliteration quadruple bonus!)
Xerxes I of Persia: Epic blunders in Greece
Antonio Lopez de Santa Ana: Napoleon of the West? Ha!
Ambrose E. Burnside: defeat from jaws of victory
Marcus Licinius Crassus Dives (Crassus): Army pincushioned by Parthians
Manuel Fernandez Silvestre - “Run! The Bogeyman is coming!”
Charles le Temeraire - Rash, rather than “Bold”
Charles Alexander of Lorraine - A sustained career of incompetence
Frederik William Stopford - Blunderer at Suvla Bay ( Gallipoli )
Emperor Romanus IV of Byzantium: Lost the Battle of Manzikert
George B McClellan - Led Union unsuccessfully
[/QUOTE]
William George Keith Elphinstone - Lost an army in Afghanistan
Douglas Haig: Lions led by donkeys
Geoffrey Spicer-Simson :went mad in dark Afrika
Francisco Solano López: almost unmade Paraguay
Curtis LeMay: tried to preemptively use nukes
Oreste Baratieri - Routed by Ethiopians at Adowa.
Lord Chelmsford - Zulu dawn at Isandlwana
Vice-Admiral Sir George Tryon - Sunk his flagship on maneouvres.
General Maurice Gamelin - Relied on the Maginot Line.
General William H. Winder - Loses Upper Canada; Washington, D.C. burns.
Benedict Arnold. Rarely has an officer of his level turned traitor.
Bill Halsey deserves a nomination at least just so we can enjoy the debate.
General John A McClernand was a useless political hack that hurt the Union’s efforts.
Douglas MacArthur – Dismissed from Korea by Truman
Nicias - commander of the Syracuse expedition
Abdel Hakim Amer - panicked, lost Sinai in 1967.
Pyrrhus of Epirus - invented new way of losing.
Daniel Sickles - almost lost Gettysburg single-handedly.*
James II of England - surrendered Britain without a fight.
Philip VI of France, crushed own army at Crécy.
Admiral Sir Cloudesley Shovell, who wrecked his fleet on the Scilly Isles: “one of the greatest maritime disasters in the history of the British Isles.”
Nitpick - sorry, I should have caught this earlier, but Mladic hasn’t been convicted, as he’s still a fugitive from justice. There’s no doubt the man did everything he’s accused of (and probably far worse besides), but “indicted scum” would be more accurate than “convicted scum.”
That list is looking real good. A true rogue’s gallery. 
I’d like to add a fifth nomination:
**
George Villiers, 1st Duke of Buckingham **- useless sycophant, incompetent military leader.
And I have my final nominee:
Zinovy Rozhestvensky - Led Russian Navy to annihilation
I’ve basically been trying to think of notable military disasters and then finding someone to blame for them :). I considered the guy who was in charge of the Spanish Armada, but thought I’d go for something that didn’t involve England or the US.