A watercolour of the marriage procession of Princess Louise to St George's Chapel, Windsor Castle on 21 March 1871. The bride is seated in a horse-drawn carriage with Queen Victoria, travelling towards the archway of the Horseshoe Cloister towards the west end of the chapel. Rows of guardsmen line the route, with crowds behind. Signed with initials and dated.

Princess Louise, the sixth child of Queen Victoria and Prince Albert, was the first British royal to marry an non-royal since 1515, when Charles Brandon married Henry VIII's sister Mary. Louise's wedding to John Campbell, Marquess of Lorne, took place in St George's Chapel in March 1871. Queen Victoria wrote of the match 'Times have changed; great foreign alliances are looked on as causes of trouble and anxiety, and are of no good. [...] As to position, I see no difficulty whatsoever; Louise remains what she is, and her husband keeps his rank...' (Letter to the Pince of Wales, 29 November 1869). The wedding in Windsor drew huge crowds.

John O'Connor was an Irish artist recommended to Queen Victoria by Lord Lorne. He is recorded as having been paid 30 guineas for this watercolour on 19 January 1875 (Royal Archives, WRA PP PEA)