In childhood, Mendelssohn had written thirteen string symphonies between the ages of twelve and fourteen. In what must pass for maturity, starting at the age of fifteen, he wrote five more symphonies for full orchestra. Symphony No.3 in A minor, Opus 56, was the second in conception and the last in order of completion. Its first inspiration came from a visit to Scotland in 1829. In April Mendelssohn had arrived in London, after an unpleasant voyage from Hamburg. Two months later in a letter to his teacher, Zelter, he mentioned his plans for the summer: After the end of London season, he projected a journey to Scotland, a country that figured largely in romantic imagination thanks to the work of Sir Walter Scott. Accompanied by his friend, Karl Klingemann, he travelled North. In Edinburgh, he recalled the story of Mary, Queen of Scots, and the murder of her secretary, David Rizzio, in the palace of Holyrood, and in the ruined chapel first entertained the idea of a Scottish symphony. Further north he could comment on the climate, remarking that the Highlands brew nothing but whisky, fog and foul weather, while the voyage by steamer to see the island of Staffa and what he described as the odious Fingal's cave, made him sea-sick. In spite of this he immediately sketched the opening theme of the Hebrides Overture, which was later revised to be performed in 1832 in London, where it won immediate popularity.