During the 1948 Arab–Israeli War, the Arab Legion was considered the strongest Arab army involved in the war. Glubb led the Arab Legion across the River Jordan to occupy the West Bank (May 1948). Despite some negotiation and understanding between the Jewish Agency and King Abdullah, severe fighting took place in Kfar Etzion massacre (May 1948), Jerusalem and Latrun (May–July 1948). According to Avi Shlaim,