Long Flight with 4 children???

We are going on an overseas trip this summer. The flight is approximately 11 hours- overnight. We have 4 children, ages 8,5,4, and 2. What are some tricks all you experienced travellers have used to keep things under control??? They are generally well-behaved, but the 2 year old is at that really active stage. I don't want to medicate, as I have seen many people recommend because it actually has an oposite effect on all my children. Any help out there would be greatly appreciated!