He was the Chancellor of the Exchequer for the 1909 budget in which he raised taxes on the rich and on employers in order to fund the Old age pension and National Insurance schemes being introduced by the Liberals against vitriolic Conservative opposition.
In the post war era his successes include the "Homes for Heroes" campaign - building houses for returning soldiers to rent; and later collaborating with the economist John Maynard Keynes who was to give the British Liberals and later much of the Western world a set of economic ideas that for financing Welfare states and mitigating economic recessions.
While Prime Minister he managed to pull off the partition of Ireland, with a compromise that kept the peace for much of two generations (and would have last longer if subsequent British governments, Conservative and Labour had not turned a blind eye to Unionists in Stormont discriminating against Northern Ireland's Catholic minority). His compromise was to create three Parliaments, one for the 6 counties of Northern Ireland, one for the 26 counties of the South and an all Ireland Parliament. The Southern Parliament never met, but the All Ireland Parliament was boycotted by the Protestants and would up a de facto state for the 26 counties - though in its constitutio it still to this day claims all 32 counties.
He lead one faction of the Liberal Party during the Liberal splits of the post war era and reunited the party briefly in the late 1920s.