A field of tulips at the Canadian Tulip Festival. The festival has grown into the largest tulip festival in the world starting from a gift of thanks given five decades ago. In the fall of 1945, Princess Juliana of the Netherlands presented Ottawa with 100,000 tulip bulbs. The gift was given in appreciation of the safe haven which Holland's exiled royal family received during the Second World War and in recognition of the role which Canadian troops played in liberating the Netherlands.