To military historians David Chandler and Richard Holmes, Marlborough is the greatest British commander in history, an assessment that is shared by others, including the Duke of Wellington who could "conceive nothing greater than Marlborough at the head of an English army".
For militærhistorikeren David Chandler er Marlborough uden tvivl den største britiske feltherre i historien, en vurdering som deles af andre, herunder Hertugen af Wellington som kunne – "ikke forestille sig noget bedre end Marlborough i spidsen for en engelske hær."