The fact that George I exclusively favored the Whigs exasperated the opposite, or Tory, party. The Jacobites or extreme members of that party (S495), in Scotland, with the secret aid of many in England, now rose, in the hope of placing on the throne James Edward Stuart, the son of James II. He was called the "Chevalier"[1] by his friends, but the "Pretender" by his enemies (SS490, 491, 512). The insurrection was led by John, Earl of Mar, who, from his frequent change of politics, had got the nickname of "Bobbing John." Mar encountered the royal forces at Sheriffmuir, in Perthsire, Scotland (1715), where an indecisive battle was fought, which the old ballad thus describes: "There's some say that we won, and some say that they won, And some say that none won at a', man; But one thing is sure, that at Sheriffmuir A battle there was, which I saw, man." [1] The Chevalier de St. George: After the birth of the "Chevalier's" son Charles in 1720, the father was known by the nickname of the "Old Pretender," and the son as the "Young Pretender." So far as birth could entitle them to the crown, they held the legal right of succession; but the Revolution of 1688 and the Act of Settlement barred them out (S497). On the same day of the fight at Sheriffmuir, the English Jacobites (S495), with a body of Scotch allies, marched into Preston, Lancashire, and there surrendered, almost without striking a blow. The leaders of the movement, except the Earl of Mar, who, with one or two others, escaped to the Continent, were beheaded or hanged, and about a thousand of the rank and file were sold as slaves to the West India and Virginia plantations (S487). The "Pretender" himself landed in Scotland a few weeks after the defeat of his friends; but finding no encouragement, he hurried back to the Continent again. Thus ended the rebellion known from the year of its outbreak (1715) as "The Fifteen." One result of this was the passage of the septennial Act (1716), extending the duration of Parliament from three years, which was the longest time that body could sit (SS439, 517), to seven years (since reduced to five years).[2] The object of this change was to do away with the excitement and tendency to rebellion at that time, resulting from frequent elections, in which party feeling ran to dangerous extremes. [2] The Triennial Act (SS439, 517) provided that at the end of three years Parliament must be dissolved and a new election held. This was to prevent the sovereign from keeping that body in power indefinitely, contrary, perhaps, to the political feeling of the country, which might prefer a different set of representatives. Under the Septennial Act the time was extended four years, making seven in all, but the sovereign may, of course, dissolve Parliament at any time. In 1911 the Parliament Act (S631) limited the duration of Parliament to five years. 536. The South Sea Bubble, 1720.