Late 80's early 90's kids programme

[trippy77]

Hi can anybody please help me , this has been driving me mad for 10 years plus ,
I remember a kids tv programme on BBc i think ?? about 2 children who travel back in time to different periods , and meet this Lord of time ! ( not doctor who ) 7 or 8 of them , and they had an adult with them who turned out to be the brother from the future , trying to trap the others ..... please some one must know ???