Sometimes I see the former, as in "starve to death".
But sometimes I see the latter as well, as in "fight to the death", or in the following quote:
I disapprove of what you say, but I will defend to the death your right to say it.
– Evelyn Beatrice Hall
When do I use which?
"To the death" is used as an idiom with verbs and nouns meaning "fight"
It means "until one party is dead" although it may be used figuratively. The expression can also occur in non idiomatic situations: "protesters reacted to the death of the man"
"To death" can be used idiomatically with a wider range of verbs meaning "until you die". For example "starve to death". It is often figurative, or hyperbolic: "I'm going to work myself to death to pass this exam." Nobody really thinks you are going to die, it is understood to be a dramatic exaggeration.
A very good question!
OALD says that both are idioms!
to death (without the article) means extremely, very much.
But when you add the article...
to the death it means until you 'die'
That's the reason, when you say starve to death, it means you are famished
But defend/fighting to the death means don't give up until you die!
Use "to death" when there is an agency or circumstance that leads to the literal cessation of life functions, e.g., "stabbed to death", "bled to death", "froze to death" etc. -- or figuratively to show an extreme situation, e.g., "bored to death", "scared to death" (although I'm sure we've all heard that people with weak hearts may make that literal) for "very bored", "very scared".
Use "to the death" when there is volition from the party to continue an effort until the party has succeeded is or dead.
Explanations
"He will starve to death." Note there is a single actor, the person who will starve until dead. While "starve him to death" involves a second and third actor it lacks the element of volition on the part of the dying party. In either case the subject necessarily dies. "Starve to the death" lacks a second actor to be in opposition and I am unaware of my having encountered such a construction.
"They will fight to the death." "I will defend to the death." In these cases there are multiple actors who will be in opposition. There are at least two interpretations.
In the quote, Miss Hall asserts Monsieur Voltaire's willingness to fight until all opposition to freedom of speech is defeated or until Voltaire has died in the struggle and can thus fight no more. It says nothing about any other party. Voltaire will fight until Voltaire has triumphed or Voltaire is dead. Similarly, a sow bears will fight to the death to defend their cubs. The sow will fight until the threat has been driven off, or the threat has been killed or until she has been killed/incapacitated (and if a sow is fighting something that can incapacitate her chances are that thing will kill her and eat her). There must be an opposing party and the willingness to fight until dead. However, unless both parties are willing to fight to the death, there exists the possibility of retreat or surrender and thus the cessation of life functions is not a requirement; the party willing to fight to the death wins without anyone dying.
Interesting question!
"To the death" means to persist until the point of death of the person taking the action. It is something you do willingly, it is not done to you, and carries the implication of self-sacrifice. The action in question may or may not be the cause of death. Sometimes you it is written as "to the end" or "to the bitter end;" these are synonymous. The phrase "to the death" rarely has a metaphorical meaning. (I say rarely but I can't think of any.)
"To death" is a variant of "unto death," and means that the action is the cause of death. It is generally not something a victim chooses willingly, it is something that is done to them.
"To death" is also a playful and informal way to say "extremely," or when using death as a metaphor for an end-point or a cessation.
Some examples:
To "love something to death" is to love very much, and is often used playfully and affectionately. Saying I "just love you to death" can come across as cute. Actual death is not implied. On the other hand to say "literally love to death" means that love was the cause of death; similarly to "love to the death", to "love until I die", or to "love until the bitter end" refers to loving until the day of my actual death.
To "starve to death" is to die as a result of starvation, while "starving to death" is a common idiom meaning very hungry. Both can be used for either meaning, but these are the usual constructions.
"Bleed to death," "starve to death," "burn to death," and "beat to death" all mean death due to a specific cause, while "done to death" refers to murder by an unspecified means. Notice that these all refer to violence or deadly situations, and are almost never used metaphorically.
The construction "half to death" means you endured some condition like bleeding or starving, but did not actually die. It is often used to exaggerate a minor incident like hunger or a small wound but which was not actually life threatening. "Beat half to death" and "beat to within an inch of my life" both mean a very severe but nonfatal beating.
"Love to death" means extreme love, "Bored to death" means extreme boredom, "scared to death" means extreme fear, and "sick to death" means extreme disgust. You can often tell by the context; boredom or fright do not cause death, so you know it is a metaphor. These constructions also usually have an object: "scared to death of X." If preceded by "literally" it means someone died in an ironic way that is usually only a metaphor. If he was "literally scared to death," it means it is ironically true; his extreme fear caused a heart attack and he died. Sickness could be a cause of death, but "sick to death" is always a euphemism, while "deathly sick" or "sick unto death" means you are so sick you are going to die.
"Arguing to death" means to carry an argument to and typically well beyond its conclusion. It implies stubbornness, bitterness, or thoroughness. Rehashing an argument that should already be finished is also called "beating a dead horse". On the other hand "arguing until you're blue in the face" means you spent all your breath arguing, and death is implied. "Arguing to the death" means to argue until the day you die; not that the argument kills you, just that you continue for the rest of your life.
To "drive a car to death" means to use it until it breaks down (dies).
In this case, "death" means dying, but "the death" means "the end", not dying, even if the implication in this instance is the same.
You can see "the death" being used to describe the end of a race, or a sports match. (E.g. At the football match, just when we thought we would go to extra time, the striker scored at the death).
to death
It means to the extent of life. To be near to die.
I beat him to death on the road
It also can figuratively point the extreme of something, extremely or very much
to be bored to death.
I'm sick to death of your endless criticism.
to the death
until somebody is dead.
a fight to the death
"to death" refers to a state. In contrast, I recall a TV show called Highlander where there was a sword fight, until "first blood". So, "to death" specifies a condition.
"to the death" refers to an event. This refers to the moment when somebody dies. This isn't referring to the state of dying, but the time or event when the dying takes place.
The difference is extremely minor. In fact, I would say that you can use the phrase "fight to death", or "fight to the death", and they are both essentially different ways to say the same thing. Both ways are technically acceptable: "fight to the death" is more common, but neither of those phrases sound particularly wrong. Therefore, I suggest that either can be used.
So, that's my technical answer. Following are just some ideas I have about how the phrases may typical be used.
Basically, referring to "the death" is typically used whenever feasible, as it tends to sound more exciting. The term is often used to imply that a death is not guaranteed. For instance, if you have two people who are fighting to the death, then there will be a death, but each individual person's death is not guaranteed. If you don't know who will be dying, then you can refer to the certain event, which is the event that somebody will die.
If you fight to the death, the idea of death might not be certain, because many fights end with at least one person not dying.
On the other hand, when death is certain, you may wish to leave off the word "the". If you take care of a person for the rest of their life, "to death", then you refer to the person's change in status (from living to dead). In this case, people typically don't say "the death", because that sounds a bit impersonal. When our sick family member is dying, who know whose death is being used, so we don't typically use the phrase "the death".
Most of he time I see "to death", to me it refers to Death visiting you at the planned end of your if, your appointed time, as it were.
To the death, implies someone will hurry the meeting of Death, and so you will force Death to come get the opponent, so, yes, some sort of Battle will take place.
