Mulled simply means heated and spiced. So you can have mulled wine, mulled cider, mulled mead, etc. No one knows the true history of mulled wine, but there was medieval mention of Ypocras or Hipocris named after the physician Hippocrates. These drinks were thought to be healthy and served as tonics in the Roman Empire. Fast forward to around 1500 and British cookbooks speak of mulling Clarrey. This was Bordeaux wine infused with honey, cinnamon and cardamom. Those Victorian English enjoyed their mulled wine, and even served a version of it, called Negus, at children´s birthday parties. If you boil the wine when making it, you can burn off the alcohol and I´m sure that´s what the Victorian parents did before serving it to a bunch of hyped on cake 5-year-olds. Most likely, the drink got its origins from wine sellers who found themselves with some spoiled product. These innovative manufacturers heated their sour merchandise, flavored it with honey and spices and ta-da, a new drink was born.