St. Odilo became abbot of Cluny in 994. Having come across Cluny often in reading about saints, I figured I should look into it a little more. The abbey at Cluny, France (Saone et Loire) was founded as a reformed Benedictine community in 910 and quickly became the gold standard of monasteries in the West. You won't be those Eastern desert monks at their own game, but if you've ever read a Redwall book, you know that western monasticism has its charms, too. (Incidentally, if you have read one Redwall book, you have indeed read them all.) But Cluny provided leadership not only in the monastic world, but also the governmental. In a world before the civil service, monasteries provided the labor pool for clerks, treasurers, and all other skilled civil administrators. The abbey lasted until the French Revolution, during which it was sacked.
Back to Odilo. He was apparently a great abbot. But other Cluniac abbots (yeah, that's a real adjective) were also really good, and they haven't made it into hagiomajor yet. The difference is two key innovations. First is All Souls Day, celebrated on November 2. Odilo established it to pray for the departed monks, but it spread from the abbeys to include, well... all souls. I like the democratic spirit that says everybody gets a feast (or at least a fast) rather than just saints. The calendar has 365 days -- surely the vast majority of us can share one of them.
His second big innovation has two parts: Pax Dei and Treuga Dei, the Peace and Truce of God. The Peace of God made it an excommunicable offense for a soldier to attack a peasant, a child, a woman, or a member of the clergy who was not bearing arms. That included stealing from churches or from peasant farmers. The idea (obviously) was that wars should be fought between combatants; those without interest or defense should be left out of it.
The Truce of God banned fighting altogether on Fridays, Sundays, during Lent, and on certain other holy days. One nice byproduct of a Friday and Sunday ban is that Saturdays usually wound up being bridged into the peace, so Odilo could legitimately be said to have invented the three day weekend.
One important thread in the history of warfare is the attempt to keep it humane. Woodrow Wilson ordered the American air corps not to attack civilian targets during WWI, even though the British were arguing that the war would be shortened if the industries supporting the enemy armies were eliminated. By World War II, there was no scruple about killing civilians, as London, Coventry, Warsaw, Dresden, Nanjing, Hiroshima, Tokyo, Nagasaki, and a thousand other places show. But at the end of the war, the concept of war crimes trials were introduced, and now we wrestle with how to be fair, consistent, and practical in our application. War is inherently anti-human, not just inhumane but anti-human. I cannot yet see how we will make sensible distinctions between war crimes and other acts of war, but I am pleased to note Odilo's place in the development of the idea.