In January Gustavus concluded a treaty with France, who agreed to pay him an annual subsidy of 400,000 thalers on the condition that Gustavus maintained in the field an army of 30,000 infantry and 6000 cavalry, and assured to the princes and peoples whose territory he might occupy the free exercise of their religion.

England also promised a subsidy, and the Marquis of Hamilton was to bring over 6000 infantry; but as the king did not wish openly to take part in the war this force was not to appear as an English contingent.

Another regiment of Highlanders was brought over by Colonel John Munro of Obstell, and also a regiment recruited in the Lowlands by Colonel Sir James Lumsden.
Many other parties of Scotch were brought over by gentlemen of rank.
Four chosen Scottish regiments, Hepburn's regiment, Lord Reay's regiment, Sir James Lumsden's musketeers, and Stargate's corps, were formed into one brigade under the command of Hepburn.

It was called the Green Brigade, and the doublets, scarfs, feathers, and standards were of that colour.

The rest of the infantry were divided into the Yellow, Blue, and White Brigades.
One evening when the officers of Reay's regiment were sitting round the campfire Lieutenant Farquhar said to Colonel Munro: "How is it that Sir John Hepburn has, although still so young, risen to such high honour in the counsel of the king; how did he first make his way ?" "He first entered the force raised by Sir Andrew Gray, who crossed from Leith to Holland, and then uniting with a body of English troops under Sir Horace Vere marched to join the troops of the Elector Palatine.