royal family of the Netherlands had moved to Ottawa until the Netherlands were liberated, and Princess Margriet was born during this Canadian exile. Princess Juliana of the Netherlands, the only child of then-Queen Wilhelmina and heir to the throne, sought refuge in Canada with her two daughters, Beatrix and Irene, during the war. During Princess Juliana's stay in Canada, preparations were made for the birth of her third child. To ensure the Dutch citizenship of this royal baby, the Canadian Parliament passed a special law declaring Princess Juliana's suite at the Ottawa Civic Hospital "extraterritorial". On 19 January 1943, Princess Margriet was born. The day after Princess Margriet's birth, the Dutch flag was flown on the Peace Tower. This was the only time a foreign flag has waved atop Canada's Parliament Buildings. In 1945, the people of the Netherlands sent 100,000 hand-picked tulip bulbs as a post-war gift for the role played by Canadian soldiers in the liberation of the Netherlands. These tulips were planted on Parliament Hill and along the Queen Elizabeth Driveway. Princess Juliana was so pleased at the prominence given to the gift that in 1946, she decided to send a personal gift of 20,000 tulip bulbs to show her gratitude for the hospitality received in Ottawa. The gift was part of a lifelong bequest. Since then, tulips have proliferated in Ottawa as a symbol of peace, freedom and international friendship. Every year, Canada's capital receives 10,000 bulbs from the Dutch royal family, celebrated in the Canadian Tulip Festival. In 1995, the Netherlands donated an additional 5,000 bulbs for Parliament Hill, 1,000 for each provincial and territorial capital and 1,000 for Ste. Anne's hospital in Saint-Anne-de-Bellevue, Que. (the only remaining federal hospital in Canada, administered by Veterans Affairs Canada) It is thought that the Netherlands and the Dutch people have had an enduring affection for Canada and Canadians long after the war, lingering into the present day. Naval warfare Battle of the Atlantic The Battle of the Atlantic was the longest ongoing battle in World War II. Once Britain declared war on Germany, Canada quickly followed, entering the war on 10 September 1939, as they had a vested interest in sustaining Britain. Canadian security relied on British success in this war, along with maintaining national security, politically speaking, some felt it was Canada's duty to assist her allies. For example, the Canadian prime minister Mackenzie King had