Four men from Fate/Zero HD Wallpaper

Four men are depicted in an anime style. On the left, a man with dark hair wears a dark blue robe and holds an open book. Next to him, a man with red hair wears a brown jacket and clenches his fist. To his right, a man with blue hair smiles and rests his chin on his hand. On the far right, a man with blonde hair wears a black jacket.