Bruce and Oliver are brothers.
I think Bruce and Oliver are brothers and nothing can stop me from thinking it.
So here is my headcanon/how they became brothers.
Oliver and Bruce met as kids. Bruce was about five and Oliver was 8. (In my little world in my head Oliver is 3 years older than Bruce, I don't know if thats true or not but I like it.)
Bruce and Oliver grew up together and when Bruce's parents were murdered when he was 9, Oliver and his parents stayed with Bruce for about 5 months until Oliver's parents said they needed to get back to Star city. Oliver visited whenever he could.
When Oliver's parents died, when Oliver was 13, on their safari tour, Bruce had him stay at the manor. While Oliver was getting used to things at the manor and his parents being gone, Bruce asked Alferd if they could have Oliver stay and if they could legally add him to the Wayne family.
After 5 or 6 months Bruce decided to ask Oliver what he thought of joining the Wayne family. It had been the first time they cried in a while when he said yes. The officially became Oliver Jonas Wayne Queen and Bruce Thomas Queen Wayne. Oliver kept his mansion in Star and him and Bruce stayed there every summer but they stayed in Gotham for the most part and they went to school together.
When Oliver graduated from Gotham Academy at the age of 18, he decided to go to college at one of the top colleges in all of Star city. Bruce graduated a year early at 16 and went to medical school until all of a sudden he disappeared, Oliver was devastated and he hired the best detectives in the world to find his little brother. When the detectives and police said that they couldn't find him and that he will be presumed dead until they find any signs of him. Oliver cried for weeks.
After a year or 2 Oliver decided to look himself on the sea he was shipwrecked on a island that was run by The League of Assassins. Right when Oliver was shipwrecked Bruce was back in Gotham and he was feeling the same devastation as his brother when he left. He looked and couldn't find him anywhere.
3 or 4 months after Bruce came back he became Batman. He fought all criminals he could find and he became the urban legend of Gotham. Bruce would also look for any information he could get his hands on to see if there was anything on Oliver. At the same time Oliver was fighting and training to get off the island and away from The League.
After 3 years Oliver finally escaped and marines found him on a raft. He was immediately brought to a hospital. Bruce flew on a plane as soon as he heard. Oliver was shocked when he saw Bruce, they hugged and cried for what felt like eternity to them. Bruce left the room and grabbed Dick and introduced him to Oliver. Oliver was shocked for a bit wondering how long he had been gone if his little brother had a son that looked to be 6.
Later Bruce explained what happened with Dick and his parents. Oliver found himself with a nephew that he was going to protect and spoiled rotten. Oliver discovered about the Batman from newspaper articles he read online and Oliver decided he was going to meet this man if it was last thing he do and make sure he doesn't hurt his family.
When Oliver finally left the hospital he went to live in Star city to officially start running Queen inc. as he had left in the hands of his father's right hand. Oliver became Green Arrow and fought crime hoping to get the Batmans attention to tell to stay away from his brother and nephew.(Robin showed up 3 years later)
5 years later, Bruce and Dick visited Oliver in Star City. The three spent the whole day together and the uncle and nephew got to spend quality time together, Oliver remembers when he hung out with Dick the first time just the two of them and he felt like was about to start sobbing when Dick called him uncle Ollie the first time. Later that night when Oliver was tieing up some goons Batman and Robin appeared. Oliver told them to stay away from him and Bruce and Dick telling them that his family was everything to him and no one can change that.
In the morning Bruce grabbed Oliver and sat him down. Oliver was shocked to learn that his little brother was Batman and that Dick was Robin. They started laughing when they all realized that they were all vigilantes and wanted to save people.
I don't have a idea about what will happen later yet but I love this AU. What should I call it?