Alexander Leslie of Auchintoul (1590–1663) was a Scottish soldier in Swedish and Russian service,[1] Russia's first General and reformer of the Muscovite army in cooperation with Boyar Boris Morozov.

Charles I of England wrote to Russian Tsar Mikhail Fyodorovich on behalf of Leslie in March 1637 saying that he was returning to Britain on private business.

Leslie, one of our faythfull subjects of our kingdome of Scotland, of noble and illustrous descent; Which letter is thrughout all our dominions, according to our imperiall requeist, shal be in all brotherlie requeist observed and performed; And that so much the more becaus your Emperial affection hath bene most enclyned to have our faythfull subjects' armes and valoris imployed in your Mateis warres, And in consideration thairof hath made our said subject Sir Alexander Leslie Major-Generall of your Mateis warlyk forces, which preferment is by ws most kyndlie accepted and greatlie esteamed, in preferring one of our Scotts subjects to such high diguitie, assureing your Matie (our dear brother) from ws that ther is no subject in our dominions, who ar willing to serve your Mateis in the qualitie of commander or souldier, bot we will give them our frie leave, consent, and libertie to serve your Matie, which we have [thought] good to certifie vnto your highnes by these our letteris, not doubting bot your Matie will at our requeist continew towards your Mateis servants our subjects all perfection and promotion; Whom we desire your Matie will continew as yow have begun to advance him, as lykwyse to performe vnto him, and all others our subjects vnder your Mateis Command, as ar mentionat in your Mateis imperiall Commission and letteris of Credence gevin vnto him: Moreover, we have, in regard of your Emperial Commission gevin to your Mateis Generall, Sir Alexander Leslie, granted libertie vnto our faytlit'ull subject Captan David Leslie for to retume him selff vnto your Mateis emperiall court ther, to attend your Mateis service, of whois wisdome, valour, and faythfulnes we have thought good to certifie your Matie as descendit from noble, illustruous, and marschall parentage, and quho in his owin persone hath gained to him selff great honour, and hath gevin sufficient prooff thairof for many yeires that he hath caryed charge in the qualitie of a Commander in the Warres of France, Germanie, Sweden, and the Low Countreyes : Therfor [having] thought good to recommend him with these our saids letteris of recommendation vnto your Matie, that he may be employed according to his qualitie, worth, and merite.

And to answer your Matie, our dear brother, gratious inclination and disposition by all princelie offices of love and respects, to manteane and preserve the amitie and mutuall correspondencie [of] long and happie continuance between our Crounes and Kingdomes : And so we leave your Matie to the protection of Almigbtie God.— From our Palace of Westminster, the 26 of Feb., in the 7 yeir of our regne of Great Britane, France, and Irland.

He was captured at Philiphaugh[8] and, by the direct intervention of Lieutenant General David Leslie, whom he had served with in Russia,[9] was dealt with leniently compared to other prisoners (most of whom were executed after the battle).