First, CONGRATULATIONS @jochi. I can't wait for this idea to kick-off.
What about this Idea?
I will call the Challenge #guesswho. In this challenge, every week, I will put a BLUR PICTURE of someone (so the person can't be easily identified), picture of someone who has made history and write a little about the person ( but not too enough so it won't give too much clue about the person), contestant will be required to make a post; in the post they would identify the person in the picture, the Full Name, A Clear Picture of the person and More history of the person beside that given on the Challenge post.
The contestant(s) who guessed correctly will be rewards. If there are 3 or more correct guesses, the reward for 1st, 2nd and 3rd position will be based on the time on entry into the contest ( time of post).
This contest will increase knowledge on History. I believe it will have great audience.
I posted this idea on your last week #brainstorming-challenge but didn't get any comment from you on it.
I know you participated with this idea and I didn't reply, but I think there is such a similar contest.
Please make a new post with your idea!