The Theotokos of the Three Hands (VIII cent.) is not, strictly speaking, a person, but an icon. Many icons have their own days in the Orthodox calendar—because they were made famous by defeating an enemy in war, for streaming myrrh, for healing some famous person, or something along those lines.
St. John of Damascus was an outspoken critic of the iconoclasts, and as such came to the attention of Emperor Leo III the Isaurian, whose minions were constantly scanning LexisNexis—I mean his Twitter feed. The emperor ratted him out to the Caliph of Damascus, who ordered that his right hand be cut off. John begged the Caliph for the hand, and, not being at all a cruel man, the Caliph gave it to him. (Or for some other reason, as seems more likely.) John placed the hand against the stump, and held it there all night as, in some discomfort, he prayed on his knees before an icon of the Mother of God. In the morning, he found that his hand had been reattached, leaving only a red scar where the break used to be. Miraculously, he did not receive a bill.
In thankfulness, he had a small silver hand attached to the icon. He carried it with him to St. Sava’s Monastery in the Holy Land, where he lived out his days as a monk. In the thirteenth century, the icon was given to (St.) Sava of Serbia (Jan 12), who took it to his homeland (Serbia) (bet you figured that out). Later, when Serbia was invaded by the Turks, the monks placed it on a donkey, prayed to the Theotokos to watch over it, and turned it loose. It wandered, unguided, back to Rivendell—just kidding, to the Holy Mountain*, and stopped before the Serbian monastery, Hilander, where it remains to this day.
Iranaeus (ca. 115–125 or 130–142 or 150—ca. 202) was born in Smyrna (modern Izmir) to a Christian family, which was no mean feat in those days, Christian families being rare on the ground. In his youth he met Polycarp (Feb 23), a disciple of John the Evangelist (see Sep 26), and may have studied under him. He became a priest (presumably by the usual method), and when things got ugly in Smryna due to the persecutions of Marcus Aurelius (great philosopher, miserable humanitarian), he was sent to Rome to present a letter to the pope outlining the evils of Montanism (a schismatic sect that practiced ecstatic prophesying in generally forbidden ways, among other things) and touting the virtues of Iranaeus (he swears he never opened it until he got there). When he returned to Smyrna he found there had been something of a slaughter of Christians, so that they needed a new bishop. Without a blench, he assumed the new role. Beyond that details about his life pretty much dry up, aside from an aside by Eusebius about his compassion on people who used the “wrong” method to calculate the date of Easter (where have we heard that before?).
What Iranaeus is really famous for, however, are his writings, the most important of which is Against Heresies, in which he argues against various heresies. (Many books in those days had titles that actually said what they were about. I find this admirable.) His principle enemies were Gnostics, about whom he had many things to say, few of them flattering. Most of his writings are lost, including the wonderfully-named On the Ogdoad, which our source claims was untitled. (Huh?) Only two of his writings remain, perhaps (it is implied) because he was an eensy teensy bit of a millenialist. But in general if you think of him as a defender of One God over and against the bizarre (from our point of view) Gnostic belief in a number of emanations (à la neo-Platonism) and an evil Demiurge, you won’t go far wrong. He is the patron of the Diocese of Mobile, Alabama. Honest.
 Yes, that’s how it’s spelled.