(Photo: Getty Images)
This year, Queen Elizabeth II is celebrating her Platinum Jubilee marking 70 years as the U.K.'s head of state. The national celebrations reach their apex next week with a four-day bank holiday weekend in which many British citizens will attend street parties in her honor. To mark the occasion, we're taking a look at 10 historic customs and traditions that Queen Elizabeth II still recognizes today. 
1. Technically speaking, the British monarch owns all of the U.K.'s swans.
This tradition dates back to the 12th century and is still, in part, exercised today. Here's what the Royal Family's official website has to say on the matter: "Today The Crown retains the right of ownership of all unmarked mute swans in open water, but The Queen mainly exercises this right on certain stretches of the River Thames and its surrounding tributaries. This ownership is shared with the Vintners' and Dyers' Livery Companies who were granted rights of ownership by The Crown in the 15th century."
2. There's very much a correct way to address members of the Royal Family.
Helpfully, it's spelled out pretty clearly on the Royal Family's official website, which states: "On presentation to The Queen, the correct formal address is 'Your Majesty' and subsequently 'Ma'am,' pronounced with a short 'a,' as in 'jam.' For male members of the Royal Family the same rules apply, with the title used in the first instance being 'Your Royal Highness' and subsequently 'Sir.'
3. Queen Elizabeth II celebrates two birthdays every year.
The first is her actual birthday, April 21, the date on which she was born in 1926. The second is her "official birthday," which is generally celebrated on the second Saturday in June. This tradition dates back to the 18th century, when King George II introduced the idea of an "official birthday" in the summer because his actual birthday, November 10, didn't provide nice enough weather for a grand public celebration.  
4. The Royal Family's incredible art collection isn't, strictly speaking, owned by them.
The so-called Royal Collection of artworks includes more than a million objects – among them, the iconic Crown Jewels on display at the Tower of London. Its value has been estimated at £4 billion ($5 billion). However, as the Royal Family's official website notes: "The Royal Collection is not owned personally by The Queen, but is held in trust by her as Sovereign for her successors and the nation."
5. Royal brides always carry myrtle in their wedding bouquets.
This myrtle comes from the garden of Osborne House, a former Royal residence on the Isle of Wight. According to the Royal Family's official website, "the tradition of carrying myrtle began after Queen Victoria was given a nosegay containing myrtle by Prince Albert’s grandmother during a visit to Gotha in Germany. In the same year, Queen Victoria and Prince Albert bought Osborne House as a family retreat, and a sprig from the posy was planted against the terrace walls, where it continues to thrive today. The myrtle was first carried by Queen Victoria's eldest daughter, Princess Victoria, when she married in 1858."

(Photo: Getty Images)
6. Queen Elizabeth II has her own bagpiper.
This tradition also dates back to Queen Victoria's reign, when Prince Albert became fond of bagpipe music during a trip to the Scottish Highlands. According to the Royal Family's Instagram account, he remarked: "We have heard nothing but bagpipes since we have been in the beautiful Highlands and I have become so fond of it that I mean to have a piper, who can if you like it, pipe every night at [our house] Frogmore." 
7. Each summer, Queen Elizabeth II hosts four garden parties.
Three of these take place at Buckingham Palace in London, while one is held at the monarch's Edinburgh residence, the Palace of Holyroodhouse. In total, these parties will be attended by around 30,000 guests, all of whom have been invited in recognition of their contribution to public life in the United Kingdom.  
8. Queen Elizabeth II officially opens the U.K. parliament every year. 
Each May, she leads the State Opening of Parliament, a pomp-filled ceremony that marks the start of the parliamentary year. Though the monarch doesn't express political opinions of her own, it is customary for her to deliver a speech outlining the government's stated aims for the year ahead.
As the BBC reports, Queen Elizabeth II missed this year's State Opening of Parliament for the first time since 1963 because of her ongoing mobility issues. Prince Charles, Prince William, and Camilla, Duchess of Cornwall attended in her place.
9. On Maundy Thursday, Queen Elizabeth II gives money to people who have helped their local community.
According to the Royal Family's official website, this tradition dates way back to 600 AD and the amount of so-called "Maundy Money" reflects the monarch's age. So for example, when she turned 95 last year, she gave 95 pence worth of Maundy money to 95 men and 95 women who had done especially good deeds. Each recipient of Maundy money is also given two small leather purses: one red, the other white.

10. When a U.K. citizen turns 100, they receive a telegram from Queen Elizabeth II.
As the government outlines on its website, a U.K. citizen also gets a telegram on their 105th birthday, and every subsequent birthday they reach from that point on.
Do you have a favorite Royal custom or tradition?