i use blockades religiously when i can. its amazing how much a little blockading can cripple ur enemy. when attacking a powerful enemy, especially one stronger than me, i blockade as many of his ports as possible 4 several yrs bfore attacking. i did this once as parthia vs julii. they (the julii) owned eastern and southern europe and all of greece. i blockaded all their ports 4 ten yrs bfore attacking. by then, most their cities had rebelled, and the rest had only 1-2 cohorts in them. i therefore utterly destroyed the julli within 4 yrs after my 10-yr blockade. it was sweet