Tenth Doctor and Elizabeth I's wedding
From Tardis Wiki, the free Doctor Who reference
In 1562, the wedding between the Tenth Doctor and Queen Elizabeth I was attended by the Eleventh Doctor, Clara Oswald and the War Doctor. This came about after the Tenth Doctor accidentally proposed to her in a ploy to prove that the Queen was in fact a Zygon. When it turned out that it was instead his horse that was the Zygon, though, he was forced to carry through with the marriage. (TV: The Day of the Doctor)