I shall not follow the various small actions of the earlier part of the campaign of 1628 in Holstein, though many of them were brilliant enough. It must suffice that Scotch and English fought constantly side by side not only against the enemy, but once riotously against the Danes themselves, whom they considered to be unduly favoured in the matter of rations. In May the Imperialists moved up in force to occupy Stralsund; and the burghers having appealed to Christian for assistance received from him the seven companies, now reduced to eight hundred men, of Mackay's regiment. [Sidenote: June 26.] On arrival their commanding officer at once selected the most dangerous post in the defences, as in honour bound, and for six weeks the regiment was harassed to death by exhausting duty. The men took their very meals at their posts, and Monro, who was now a major, mentions that he never once took off his clothes. They suffered heavily too from the enemy's fire, a single cannon shot strewing the walls with the brains of no fewer than fourteen men; but still they held out. At last Wallenstein came up in person, impatient at the delay, and vowed that he would take the town in three nights though it hung by a chain between heaven and earth. His first assault was hurled back by the Scots with the loss of a thousand men. But the Highlanders also had been severely punished; three officers and two hundred men had been killed outright, and seven more officers were wounded. On the following night the attack was renewed and again repulsed, but the garrison was now compelled to open a parley in order to gain time; and the negotiations were prolonged until the arrival of a second Scottish regiment under Lord Spynie enabled the defenders to renew their defiance. [Sidenote: 1630.] [Sidenote: February.] Shortly after the King of Sweden charged himself with the defence of Stralsund. Alexander Leslie, whom we shall meet again, was appointed to take the command, and Mackay's and Spynie's regiments after a final sortie were withdrawn to Copenhagen. Of Mackay's, five hundred had been killed outright in the siege, and a bare hundred only remained unwounded; in fact the regiment required virtually to be reconstructed. The work of recruiting and reorganisation occupied the winter months, at the close of which the corps, now raised to ten companies and fifteen hundred men, was honourably discharged from the service of Denmark, and free to join itself, as it presently did, to Gustavus Adolphus. Its first duty was to learn the new drill and discipline introduced by the King of Sweden; and as his system was destined to be accepted later by all the armies of Europe, no better place can be found than this, when it was just brought to perfection and first taught to British soldiers, to give some brief account of it.