From rogueclassicism this day in history
ante diem iii idus decembres
Agonalia — the fourth and final occurrence of this festival in the Roman calendar; like all instances, the Rex Sacrorum would sacrifice a ram in the Regia, but on this occasion, the sacrifice was apparently in honour of Sol Indiges.
Septimontium — a somewhat obscure festival apparently originally only celebrated by the ‘montani’ (i.e. the ‘hill-dwellers’) which involved sacrifices on each of Rome’s seven hills.
287 — martyrdom of Fuscian (and others)
302 — martyrdom of Pontian
Sol Indiges was the forerunner of Sol Invictus.
Rex sacrum
Nope, Rex Sacrorum, as written. Sacer is 1st/2nd declension, not 3rd. The Rex Sacrorum inherited the sacral duties of the king after the abolition of the monarchy.
On a Latin oriented tangent, though I’m sure many readers here already know about it, if you download this http://sourceforge.net/project/showfiles.php?group_id=145496 you get a free software version of Lewis & Short. It’s very handy when you need L&S but don’t have room in your suitcase, for example.
There is also this from the Perseus Project at Tufts. Very thorough. http://www.perseus.tufts.edu/cgi-bin/resolveform?lang=Latin. Full Lewis & Short for Latin and Liddell Scott for Greek.
sacrum is genitive plural: v. Allen & Greenough,
49 d.
Just to clarify my comment, it should have been “or”
rex sacrum. Rex sacrorum is obviously correct, but I
was just trying to show the archaic form.