<P> Residential design was a direct development from Ubaid houses . Although Sumerian cylinder seals depict reed houses, the courtyard house was the predominant typology, which has been used in Mesopotamia to the present day . This house called é (Cuneiform: 𒂍, E; Sumerian: e; Akkadian: bītu) faced inward toward an open courtyard which provided a cooling effect by creating convection currents . This courtyard called tarbaṣu (Akkadian) was the primary organizing feature of the house, all the rooms opened into it . The external walls were featureless with only a single opening connecting the house to the street . Movement between the house and street required a 90 ° turn through a small antechamber . From the street only the rear wall of the antechamber would be visible through an open door, likewise there was no view of the street from the courtyard . The Sumerians had a strict division of public and private spaces . The typical size for a Sumerian house was 90 m . </P> <P> The palace came into existence during the Early Dynastic I period . From a rather modest beginning the palace grows in size and complexity as power is increasingly centralized . The palace is called a' Big House' (Cuneiform: E. GAL Sumerian e-gal Akkdian: ekallu) where the lugal or ensi lived and worked . </P> <P> The palaces of the early Mesopotamian elites were large - scale complexes, and were often lavishly decorated . Earliest known examples are from the Diyala River valley sites such as Khafajah and Tell Asmar . These third millennium BC palaces functioned as large - scale socio - economic institutions, and therefore, along with residential and private functions, they housed craftsmen workshops, food storehouses, ceremonial courtyards, and are often associated with shrines . For instance, the so - called "giparu" (or Gig - Par - Ku in Sumerian) at Ur where the Moon god Nanna's priestesses resided was a major complex with multiple courtyards, a number of sanctuaries, burial chambers for dead priestesses, and a ceremonial banquet hall . A similarly complex example of a Mesopotamian palace was excavated at Mari in Syria, dating from the Old Babylonian period . </P> <P> Assyrian palaces of the Iron Age, especially at Kalhu / Nimrud, Dur Sharrukin / Khorsabad and Ninuwa / Nineveh, have become famous due to the Assyrian palace reliefs, extensive pictorial and textual narrative programs on their walls, all carved on stone slabs known as orthostats . These pictorial programs either incorporated cultic scenes or the narrative accounts of the kings' military and civic accomplishments . Gates and important passageways were flanked with massive stone sculptures of apotropaic mythological figures, lamassu and winged genies . The architectural arrangement of these Iron Age palaces were also organized around large and small courtyards . Usually the king's throne room opened to a massive ceremonial courtyard where important state councils met and state ceremonies were performed . </P>

Why were royal palaces introduced to mesopotamian cities
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