It’s called a transom.

You can hang curtains above the transom’s

You don't need any curtains or draperies with those period appropriate venetian blinds.

Those shutters are perfect for those windows.

You can do srapes on some arch windows, but 1/4 arches only allow drapes below the 1/4 arch.

I would be removing all those shutters! Why have large windows and then block a big percentage of the glass, and views, with shutter frames and bars?

I like to use thin profile cellular/Duette shades for sun control or privacy, when needed, and stationary panels to add color/softness. Maximizing the windows light and views most of the time.