Ah, the Annals. Really the starting point for figuring out Pepin and Charles, when working from the primary sources. Punchy, pithy, and without (much) guile, the Annals are a readable, and even enjoyable, year-by-year chronicle of the doings of the great and the good and the not so good in the Frankish kingdom.
The Annals begin in 741, with, “Charles, mayor of the palace, died,” and that’s it. Which is perhaps the soul of brevity. However there are two versions of the Annals: the original, terser version, and the one called “Revised” by the scholars. The Revised version for 741 goes on to include news about Charles’ three sons, and the beginnings of a fantastic family drama, worthy of Tolstoy, that played out over the next few years. The translations I’ve seen show the original version, and then any emendations by “the Revisor.” The multiple authors of the Annals are unknown, but putting forth candidates and shooting them down seems to be great sport in academia.
One of the confusions I’ve had with the chronicle is that the new year started at Easter, so “the spring of 778” can be somewhat problematic. But perhaps no worse than modern times – is January part of “the winter of 2014,” or 2015? Anyway, just something to keep in mind if you’re trying to pin down the exact date of some event.
One of my favorite parts of the Annals are the occasional mention of natural (and unnatural) events. In 772 Charles’ army was suffering from thirst, when suddenly “so much water poured forth in a stream that the whole army had enough.” Saxons fled the battlefield stricken with terror in 776 when they “saw the likeness of two shields red with flame wheeling over the church.” Eclipses, famines, and plagues are mentioned.
The most common translation available is by Scholz. The volume includes a good introduction and a half-dozen simple maps, which at least give you some basic idea of the geography under discussion.