I see this style of A (an extra bar on top) pop up in manuscripts. Does anybody know any good historical fonts, preferably free, that have an A like this? Another example is Dürer's monogram: https://commons.wikimedia.org/wiki/File:AlbrechtD%C3%BCrer01.jpg

http://www.dafont.com/theme.php?cat=403&text=A&fpp=50&sort=alpha

This not only medieval style, this is basque style.

Yes, that's quite likely, and as Koeiekat said, it also seems to show up in Celtic fonts (though those may just as well be fantasy fonts, they regrettably lack a description).

A friend of me pointed me to this: http://www.gutenberg.org/files/20590/20590-h/20590-h.htm It points to Anglo-Saxon use as well.

Anybody have any idea what this sort of lettering is called?

Lombardic may be?

http://www.dafont.com/search.php?q=lombardic&text=A

https://www.google.es/search?q=lombardic+fonts&client=firefox-a&rls=org.mozilla:en-US:official&tbm=isch&tbo=u&source=univ&sa=X&ei=3vI6Ur3ZH6TC7AaQpYHYDg&ved=0CDAQsAQ&biw=1232&bih=738&dpr=1