Peace and security being established in his dominions, he convoked an assembly of the states and declared his son Malik Shah his heir and successor.
After the death of Malik Shah the head of the family was not strong enough to enforce obedience, and consequently the central government broke up into several independent dynasties.
Malak-bel has been explained as " messenger of Bel "; but more probably Malak is the common Babylonian epithet malik given to various gods, and means " counsellor "; Malak-bel will then be the sun as the visible representative of Bel.
Till the year 1079 the Persian year resembled that of the ancient Egyptians, consisting of 365 days without intercalation; but at that time the Persian calendar was reformed by Jelal ud-Din Malik Shah, sultan of Khorasan, and a method of intercalation adopted which, though less convenient, is considerably more accurate than the Julian.
The city possesses five gates, two on the northern face, the Kutab-chak near the north-east angle of the wall, and the Malik at the re-entering angle of the Ark-i-nao; and three others in the centres of the remaining faces, the Irak gate on the west, the Kandahar gate on the south and the Kushk gate on the east face.