Lagash. Gudea, ruler of Lagash (reign ca. 2144 to 2124 BC), was a great patron of new temples early in the period, and an unprecedented 26 statues of Gudea, mostly rather small, have survived from temples, beautifully executed, mostly in "costly and very hard diorite" stone. These exude a confident serenity. The northern Royal Palace of Mari produced a number of important objects from before about 1800 BC, including the Statue of Iddi-Ilum, and the most extensive remains of Mesopotamian palace frescos. The Neo-Sumerian art of the Third Dynasty of Ur reached new heights, especially in terms of realism and fine craftmanship. Amorite and Kassite periods (c. 2000–1100 BC) The political history of this period of nearly 1000 years is complicated, marked by the rise of Semitic-speaking polities originating in northwestern Mesopotamia. The period includes the Amorites Isin-Larsa Period and the First Babylonian Dynasty or Old Babylonian period (c.1830–1531 BC), an interlude under the rule of the Kassites (c. 1531–1155 BC) followed by invasions of the Elamite, while the Middle Assyrian Empire (1392–934 BC) developed in the northern part of Mesopotamia. The period ended with the decisive advent of the Neo-Assyrian Empire under Adad-nirari II, whose reign began in 911 BC. Isin-Larsa period (c. 2000–1800 BC) The Isin-Larsa period is a period of turmoil, marked by the rise of the influence of the Amorites for the northwest of Mesopotamia. Life was often unstable, and non-Sumerian invasions a recurring theme. First Babylonian Dynasty (1830–1531 BC) From the 18th century BC, Hammurabi (1792 BC to 1750 BC), the Amorite ruler of Babylon, turned Babylon into a major power and eventually conquered Mesopotamia and beyond. He is famous for his law code and conquests, but he is also famous due to the large amount of records that exist from the period of his reign. During the period Babylon became a great city, which was often the seat of the dominant power. The period was not one of great artistic development, these invaders failing to bring new artistic impetus, and much religious art was rather self-consciously conservative, perhaps in a deliberate assertion of Sumerian values. The quality of execution is often lower than in preceding and later periods. Some "popular" works of art displayed realism and mouvement, such as the statuette of a walking four-headed god from Ishchali, attributed to the period between 2000–1600 BC. The Burney Relief is an unusual, elaborate, and relatively