Meanwhile, schemes were hatched to reconquer Jerusalem through Egypt. A Fourth Crusade was planned after the failure of the Third, but it resulted in the sack of Constantinople in 1204, and most of the crusaders involved never arrived in the kingdom. Aimery, however, not knowing of the diversion to Constantinople, raided Egypt in advance of the expected invasion. Both Isabella and Aimery died in 1205 and again an underage girl, Isabella and Conrad's daughter Maria of Montferrat, became queen of Jerusalem. Isabella's half-brother John of Ibelin, the Old Lord of Beirut governed as regent until 1210 when Maria married an experienced French knight, John of Brienne. Maria died in childbirth in 1212, and John of Brienne continued to rule as regent for their daughter Isabella II.