Traditionally it's made from red wine, brandy, chopped fruit, honey, and gaseosa (reduced sweetness lemonade).
I make mine using red wine, brandy, fresh orange juice, lemonade & slices of fruit.
Figi, I have in my possession a Spanish book dating from the 1800's which says honey was the traditional sweetener for sangria.
There is no definitive recipe for sangria - there are dozens of varieties.
Sangria (derives from the spanish word "Sangre" which means blood) hence the colour.
The recipes of each province do have subtle differences, however, it is principly made from red wine (ideally Rioja) Gaseosa (Lemonade) and various fruits that are diced(citrus)
"Salud" (Cheers)