Mike set about raising £5000 : BEGIN, start, commence, go about, get to work on, get down to, embark on, tackle, address oneself to, undertake.
the youths set about him : ATTACK, assail, assault, hit, strike, beat, thrash, pummel, wallop, tear into, set upon, fall on; informal lay into, lace into, pitch into, let someone have it, do over, work over, rough up, knock about/around; Brit. informal duff up, have a go at; N. Amer. informal beat up on.
2192; headword