Prepare the Orange: Slice half the orange into thin rounds.
Combine the Ingredients: In a large pot, combine the red wine, sliced orange, cinnamon sticks, star anise, cloves, and sugar.
Simmer the Drink: Bring the mixture to a simmer over medium heat. Reduce the heat to low and let it simmer for 15-20 minutes to allow the flavors to meld together.
Add the Brandy: If using, stir in the brandy.
Serve: Ladle the Hot Mulled Wine into mugs, making sure to strain out the spices. Serve warm.