Operation Downfall, the planned Allied invasion of Japan at the end of WWII, would be classified in military nomenclature as a "campaign" involving several pitched battles between the invading Allied and defending Japanese forces. In terms of a single battle, this is a difficult question to answer, as the operation itself never took place. However, by analyzing both US and Japanese plans for attacking/defending the home islands, we can get a fairly good idea of how the campaign would have played out.
The first phase of "Downfall," Operation Olympic, targeted the southernmost Japanese Home Island of Kyushu. According to D.M. Giangreco's 2009 book "Hell to Pay: Operation Downfall and the invasion of Japan, 1946-1947," the forces assigned to the US Sixth Army, which was given the task of securing approximately one-third of that island, would have numbered roughly 766,700 in 14 divisions (with apparent provision for reinforcement by six additional divisions), while the defending Japanese 16th Area Army (Army Group/Front Equivalent) numbered about 917,000 in 15 divisions (plus an antiaircraft division) and 10 brigades, plus the Iki and Tsushima fortress units. The Japanese, if need arose, also had provision for reinforcements of up to four additional divisions from Honshu.
However, as mentioned above, 'Olympic' as a whole represents not a battle, but a campaign.
The most plausible prospect of seeing a 'record-breaking' single battle rests with the second phase of "Downfall:" Operation Coronet, the invasion of the Tokyo area at the Kanto Plain.
In order to achieve final victory over Japan, the Allies realized they needed to control Tokyo. Since the Japanese realized not only this blatant Allied objective, but also the rough US plan of invasion, they organized their forces to ensure that the 'Yankee Barbarians' would be crushed by one fell swoop on Honshu. According to Giangreco, the initial Allied invasion of Honshu during 'Coronet' would consist of the US First and Eighth Armies, organized into 28 divisions and 1,069,000 ground and air personnel, with reinforcements arriving in the form of 12 divisions of the US Tenth Army and the British "Commonwealth Corps," comprising an unknown, but presumably large, number of personnel. To defend Tokyo, the Japanese 12th Area Army could muster 22 divisions and 14 brigades of unknown numerical strength (Giangreco cites total Japanese regular troop strength in the Home islands as roughly 2,900,000. With ~900,000 already earmarked for the defense of Kyushu, it is reasonable to estimate that at least half of the remainder would be somewhat involved in the climactic struggle for the capital), plus plans for reinforcement by as many as 5 additional divisions from areas outside the Area Army's jurisdiction. Since this military operation would focus almost exclusively on the capture/defense of Tokyo, and was referred to by both sides as a coming 'decisive battle,' it could be fairly be referred to as such.
Thus, the final balance sheet in the hypothetical "Battle of Tokyo" would have looked something like this:
12th Area Army (Japan): 27 divisions and 14 brigades
vs
1st, 10th, and 8th Armies (USA/British Commonwealth): 40 divisions plus unknown smaller formations.
It is also important to note that the Japanese also had access to a large pool of civilian militia, called the Patriotic Citizens' Fighting Corps. Giangreco puts the strength of this organization at roughly 28 million(!), compared to the total Japanese population of ~73,000,000. This is in addition to the 1,300,000 civilians already working for the IJN and 2,250,000 working for the IJA. Such huge numbers of militia and paramilitary personnel would ensure that any large-scale confrontation would be unimaginably bloody, on top of the massive civilian casualties that would inevitably result from the fighting in the Tokyo Metropolitan Area.
Thus, it can be safely assumed that the cancelled Invasion of Japan might have produced a land battle that could be called the 'largest' and 'bloodiest' of all time, given the data we have on the opposing forces in terms of their raw numerical strength.
Don't believe Hollwood movies.
Hitler planned and executed an operation to exterminate (murder) the Jews in Europe.
He was executed by firing squad.He was executed by firing squad.He was executed by firing squad.He was executed by firing squad.He was executed by firing squad.He was executed by firing squad.He was executed by firing squad.He was executed by firing squad.He was executed by firing squad.He was executed by firing squad.He was executed by firing squad.
Dick Turpin was hanged. It seems he actually performed the act himself by stepping off the support he was on at the gallows.
People were being executed for reasons other than actually being guilty.
Every other option available to the Allies would have resulted in greater loss of life. The bombs, in the words of President Harry S. Truman, represented the "least abhorrent choice." See related answers on this site for more information. (spelled as they appear here) ("Would Operation Downfall have been the largest and costliest battle in history if it was actually executed?") ("Why did the US refuse to accept japans terms for surrender?")
The old Lord of Cawdor was executed for treason, after betraying King Duncan of Scotland and attempting to overthrow him. His disloyalty and treachery led to his downfall and his title being given to Macbeth.
limited intervention
Actually he tried to kill himself but he was unsuccessful and Japan executed him for the war crimes.
A covert operation would be some sort of attack, that was executed in a way to conceal the identity of the aggressor. This is often referred to as Cove Ops or Covert ops by the Military.
The Inca leader during Francisco Pizarro's conquest of the Inca Empire was Atahualpa. He was captured and executed by the Spanish conquistadors, leading to the downfall of the Inca Empire.
During the French Revolution more than 18,000 revolutionists were executed. Some of have said that nearly 40,000 revolutionists were actually executed.
Actually, he did both.
Don't believe Hollwood movies.
The Instruction Register (IR) stores the instruction currently being executed. In simple processors each instruction to be executed is loaded into the instruction register which holds it while it is decoded, prepared and ultimately executed.
His son Saturn overthrew him from his kingdom and executed him.
Hitler planned and executed an operation to exterminate (murder) the Jews in Europe.