The Prophet salla Allahu alaihi wa sallam ruled that any marriage that takes place without the consent of the guardian (Wali) is void.

Sir i want to know whether a marriage without vali is valid or not. There were two witness and brides sister was present at the time of marriage. Mahar was given, eejab qabul was done and qutba was recited. Nobody from the brides side was present at the marriage except her own sister( blood sister). Is this marriage valid