Moscow Art Theatre is a 
Russian event. It signifies the premiere of Checkovs play The Seagull.
It can happen any time between 1899 and 1902 without any other requirement. It has a mean time to happen of 5 months, which decreases by 25% after 1900 and again by 5% after 1901.
It gives Russia 5 prestige with no drawbacks.
Strangely, the event doesn't actually require that Russia owns Moscow.
Event decription
The production style of Checkov's The Sea Gull has shown that the Moscow Art Theatre is almost single-handedly taking the Russian theatre into the twentieth century.