4.

Connect the following nine pictures. Do try not to Back-Image Search...

• First pic is not a fort (and not the Great Wall). It is synonymous to 'fort' though. A stronghold into which people could go for shelter during a battle.
• For the sixth pic, think "strategic"ally.
• There are no more clues (People may find it pretty simple actually).
• Not in order. Not exhaustive.

.

Dela gets it right. Followed by Jetty, but should I mention that? But, jetty got more military Ops right. Brilli-aunto...

All military ops of the Second World War:

Barbarossa (a giveaway) - Nazi invasion of Russia,

Citadel - Tank battle of Kursk,

Felix - Taking of Gibraltar,

Dragoon - Allied invasion of South France

Eagle - Battle of Britain,

Operation Summernight's Dream

Overlord - Normandy,

Uranus - Russian counteroffensive,

Torch - Allied African landings (vs Rommel)

And since DeLa gets it right, he will be given the opportunity to give a chapo to everyone else.