A Christmas ham or Yule ham is a traditional dish associated with modern Christmas and historical Yule. The tradition is believed to have begun among the Germanic peoples as a tribute to Freyr, a god in Germanic paganism associated with boars (see Sonargöltr), harvest and fertility.
According to some folklorists and historians the Christmas ham's origins in England lay in a:
"tradition [that] was initiated in all probability on the Isle of Britain by the Anglo-Saxons, although our knowledge of it comes substantially from medieval times....[In ancient Norse tradition] sacrifice carried the intent of imploring Freyr to show favor to the new year. The boar's head with apple in mouth was carried into the banquet hall on a gold or silver dish to the sounds of trumpets and the songs of minstrels."
In Scandinavia and England, Saint Stephen may have inherited some of Freyr's legacy. His feast day is 26 December and thus he came to play a part in the Yuletide celebrations which were previously associated with Freyr. In old Swedish art, Stephen is shown as tending to horses and bringing a boar's head to a Yuletide banquet. Both elements are extra-canonical and may be pagan survivals.
The Christmas ham (Yule ham), is often associated with modern Christmas. 
Swedes celebrate Christmas in many different ways, and many of the local customs and specialties still survive. A small selection of classic dishes for a Swedish Christmas meal (julbord) include Christmas ham (which is first boiled; then painted and glazed with a mixture of egg, breadcrumbs, and mustard; and then baked), pork sausage, an egg and anchovy mixture (gubbröra), herring salad, pickled herring, home-made liver pâté, wort-flavoured rye bread (vörtbröd), potatoes, and a special fish dish.)
Ham is a traditional Australian dish that features on most tables on Christmas Day. It is cooked and served in many ways all around Australia, with many families adding their own secrets to the ham, making it a special aspect of a Christmas lunch or dinner.
Christmas in Australia comes at the beginning of summer, and many people no longer serve a traditional hot roast dinner. Cold turkey and ham, seafood, and salads are often served instead. Furthermore, the Christmas ham leftovers are often frozen so to make soup and other dishes when the summer is over.