property of Queen Elizabeth II

"In the United Kingdom there is a popular belief that all swans are the property of the reigning Monarch. In fact their right to ownership of swans is restricted to unmarked Mute Swans on open water, and this right is exercised only on certain stretches of the River Thames and some of its tributaries between Windsor and Abingdon. However, strictly speaking the British swans are the property of the Queen..." { wikipedia }