"The Night Watch" by Rembrandt, 1642.

It was a portrait commissioned by a militia company in Amsterdam. Militia company portraits were pretty common in Dutch paintings at this time, but this one was pretty unique in its composition. The portraits were usually done very flat, with all the members simply standing or sitting and facing the viewer, but Rembrandt painted the Militia Company of District II in this more exciting way with them moving around an in action.

Theres also a theory that the painting includes clues left by Rembrandt to accuse the company of murdering their previous captain over financial reasons as well as other crimes and immoral acts by the officers. The theory also states that these officers, all wealthy and powerful men, realized this after the fact and worked behind the scenes to ruin Rembrandts career.