 Andrew II decided to return home , leaving the crusaders ' camp with Hugh I and Bohemond IV in early 1218 . Although military action was suspended after their departure , the crusaders restored fortifications at Caesarea and Atlit . After new troops arrived from the Holy Roman Empire in April , they decided to invade Egypt . They elected John supreme commander , giving him the right to rule the land they would conquer . His leadership was primarily nominal , since he could rarely impose his authority on an army of troops from many countries . 
