It is often affirmed that international arbitration does not have a forum. This statement can be seen as one of the manifestations of the doctrine that considers arbitration as a purely international phenomenon, detached from national laws. I have criticised this doctrine in many writings and will not repeat my arguments here.1 What this chapter deals with is one specific aspect, namely the significance for international arbitration of the arbitration law of the country in which the arbitral tribunal has its formal seat, the lex arbitri. The analysis will show that the statement according to which arbitration has no forum cannot de understood to mean that the lex arbitri has no significance for arbitration.