The painting is called "La mort de Sardanapale" and can be find in the Louvre in Paris.
Sardanapale was a king of Assyria who knowing he would get caught by his opponents, killed all his family, wives, and animals (throat slashing...). It was hugely scandalous when the painting was first shown in 1827, because of the cruelty and clear opposition to the academics.
It's now considered a real masterpiece. And unlike most Delacroix's paintings, it's not big at all!