What is an ablative absolute?

Ablative absolutes are a common type of phrase found in Latin. They seem a little complex at first, but once you learn to recognise them, they are one of the easiest kinds of phrase to notice and translate in Latin. 

Simply, an ablative absolute is a phrase consisting of a noun in the ablative case, and a participle, also in the ablative case, in agreement with the noun.

The basic non-idiomatic way of translating an ablative absolute is 'with something being done/on the point of being done/having been done.'

What is important to remember is that the ablative absolute is independent of the rest of the sentence in the construction. The noun and the participle have NO bearing on the rest of the sentence. One thing I find really useful when I'm translatin Latin and I come across as an ablative absolute, is to put brackets around the noun and the participle, to make it obvious that they are completely separate.

The participle in the ablative absolute can be found in different tenses, and we take the meaning from there.

So, for example:

Regibus exactis consules creati sunt

With kings having been abolished, consuls were elected

Note that 'exactis', the ablative participle, is in the perfect tense, and so we translate it as 'having been abolished'

Take another example

Caesare venturo, Phosphore, redde diem

With Caesar about to arrive, Morning Star, restore the day

Here, 'venturo', the ablative participle, is in the future tense. And so we translate it as 'about to arrive' or 'on the point of arriving'

It's simple. Recognise a noun and participle construction in the ablative, look at the tense of the participle, and there you go.