Stapel duly attacked Prague, how it didn't fall I do not know, I was left with 3 - 4 only just alive troops, one of which was a donated infantry. Stapel however made the mistake of attacking from a tile within reach of another of my cities. I attacked with everything that could reach including Spears and Archers, backfilling the now empty city with troops from elsewhere. I did however manage to reduce his stack down to 10 very injured troops.
I moved whatever could reach Prague into the city and hoped for the best, fully expecting it to fall next turn. At least it has reduced the cost of unit support!