Clarke seized the opportunity to expand British influence. First, he called all Chinese secret societies together and demanded a permanent truce. Later, through the signing of the Pangkor Treaty on 20 January 1874, Clarke acknowledged Raja Abdullah as the legitimate sultan of Perak. It resulted in the appointment of J.W.W. Birch as a British resident in Perak later that year. Raja Ismail, on the other hand, while not party to the agreement, was forced to abdicate due to intense external pressure applied by Clarke.