It's an illustration for the fanfic "One guard's chronicles"
"Eternal memory and glory to the Heroes!
To the guards of Celestia and Luna, who did not spare their lives and stopped the enemy by their chests.
Simple townspeople and villagers, who died in those terrible days.
Archers truly noble bandits of forest roads, that came with sir Timberhost, to the defend of our city, and fought to the their last breath.
Former ConArm soldier, who showed that in their ranks there are still those who remember what «honor» means, and about which we know only that his name is Soulstrey, but we will remember him forever.
And to all those who gave their lives to protect our foals."
P.S. That is not Pinkie Pie. I don't know what I was thinking about when I drew this random pony.