Felix Mendelssohn's "Wedding March" in C major, written in 1842, is one of the best known of the pieces from his suite of incidental music (Op. 61) to Shakespeare's play A Midsummer Night's Dream. It was written in 1842, and it is one of the most frequently used wedding marches, generally being played on a church pipe organ.

The first time that Mendelssohn's "Wedding March" was used at a wedding was when Dorothy Carew wed Tom Daniel at St Peter's Church, Tiverton, England, in June 1847 when it was performed by organist Samuel Reay. However, it did not become popular at weddings until it was selected by Victoria, The Princess Royal for her marriage to Prince Frederick William of Prussia in January 1858. The bride was the daughter of Queen Victoria, who loved Mendelssohn's music and for whom Mendelssohn often played while on his visits to Britain.

More Info: en.wikipedia.org