Marcus Aurelius - The Stoic Emperor

Today is not only St. Patrick's Day but the anniversary of the death of the Roman Emperor Marcus Aurelius, who died from the same plague that wiped out millions in the Empire at that time.  This was at Vindobono, modern day Vienna, on the Danube River, when he died in 180 AD after four years of holding back a Germanic incursion into the heart of the Empire.  Thus he kept the Roman Empire breathing room for a century before further problems developed, leaving the Empire vulnerable to outside incursions.

Rome had a running battle with barbarians almost from its start: the Gauls sacked Rome in 387 BC, they invaded in 225 BC, in 113 Germanic tribes defeated Roman armies and invaded Gaul and Spain, in 102 BC Marius defeated part of them, in 9 AD an entire legion was lost in the Teutoburg Forest, in the years up to 180 AD we have Aurelius preventing a breakthrough by Germanic tribes, in 255 Goths invade Macedonia and later Greece, in 378 Visigoths defeat the Eastern Emperor at Adrianople,in 410 they sack Rome. 

So aside from being a brilliant advocate of Stoicism in his Meditations, Aurelius sacrificed his comfort and life to preserve civilization from the recurrent barbarian incursions and thus kept the flame of Greco-Roman culture going longer than it might have.