The custom of giving goes back into ancient history. The Druids used to make a gift of their holy plant mistletoe, during the Winter Solstice Celebrations, for good luck in the coming Year. This developed into gifts of food or fuel to help neighbours throughout the rest of the winter.
In ancient Rome, gifts were exchanged during the New year's celebrations. At first these gifts were simple, such as a few twigs from a sacred grove or food. Many gifts were in the form of vegetables in honour of the fertility goddess Strenia. The Romans had a traition of presenting the Emperior and each other with good luck tokens, called 'Strenae'. This practice was usually an effort to receive special favours or to impress, which led to more precious gifts being given, like clothing, silver, or gold items.
While most of this giving was done on a voluntary basis, history has had its share of leaders who did their best to ensure they would have plenty of gifts to open. One year Emperior Caligula of Rome delcared to all that he would be receiving presents on New Year's Day. The gifts he thought to be inadequate of his stature were ridiculed.
Similarily, one December, Henry III decided to close down the Merchants of England, because he was not impressed with the amount of monetary gifts they had give him.
As Christianity spread and gained official status. Early church leaders tried to outlaw the custom of exchanging gifts, but people wouldn't stop, so instead, the Christian leaders turned it to their advantage by finding a justification for it. They came up with 'The Magi's Act of bearing gifts to the infant Jesus'. The idea was that Jesus was a gift from God to the world, bringing redemption and everlasting life, but, because we could not give gifts to God, we gave them to each other instead!
The gift giving we are most familiar with stems from the Victorian Era. The Victorians, brought a renewed warmth and spirit to Christmas, and made family the most important part of the celebration. During the Christmas season, many Victorians filled their hearts with friendliness and charity, so it was natural for them to give gifts. They put a great deal of thought and preparation into their christmas's. Traditionally a holiday filled with merriment, It was poplular to have a 'Cobweb Party'. At this party, each family member was assigned a colour, and then shown to a room criss-crossed with various coloured wools, to symbolise a cobweb. They followed their colour through a maze until they reached the present tied to the end of it. This was theirs to keep.
Another favourite was the 'Christmas Pie'. This was not a particularly edible pie. Small gifts were hidden in a bowl of grain, and everyone would take turns to dip a spoon in to it. Whatever treat was in their spoonful was theirs to keep.
In later times in England and America the influence of the Victorians was added to with the addition of St Nicholas for the English, and Santa Claus by the Americans, claiming he/they, were responsible for the appearance of presents left under the Christmas Tree.