This dissertation engages with multiple temporalities of a single, paradigmatic site in southern Mesopotamia (modern-day Iraq) named “Tello” in Arabic and “Girsu” in Sumerian. The large-scale excavations at this site carried out by a team led by the French diplomat Ernest de Sarzec from 1877 onwards marked the “discovery” of the “Sumerians” and triggered an archaeological sensation in Europe. I bring the art history of this site from the third millennium BC into the present by constructing what I call a “site-world:” the totality of material encounters across time and space discussed not in isolation but as embedded in an understanding of the mutual constitution of past and present, and of object and subject. This analysis relies on two main, methodological interventions, both of which emerge from a comprehensive critique of existing disciplinary practices. First, I expand the range of sources to be consulted by reaching across disciplinary boundaries and incorporating local accounts that have been systematically neglected. These sources span from official records such as the Ottoman Imperial Archives to the diaries of individuals such as the steamship employee Joseph Mathia Svoboda. Instead of relying on Eurocentric archaeological narratives based on individual glory, I investigate the material foundations for archaeological research and demonstrate the existence of local and international networks characterized by asymmetrical relationships that were sustained by nineteenth-century colonialism. Second, I expand the temporal range of analysis by reaching across time periods and incorporating those eras that have been left out of prevailing art historical and archaeological narratives. Critiquing the scholarly reliance on narratives of nineteenth-century “discovery” in a putative terra incognita, I investigate ancient, Hellenistic, and Medieval Arabic sources and include “pre-discovery” histories of local engagement with the site of Tello. I show that the enlistment of the putatively self-evident notion of “discovery” as an explanatory model served to gloss over the millennia-long histories of local engagement with ancient Mesopotamian sites. In accordance with these two methodological interventions, I carry out formal, iconographical, material, and contextual analysis of artworks from Tello in conjunction with critical readings of ancient Sumerian texts, Medieval Arabic accounts, and late Ottoman archival documents on their design, production, excavation, transportation, and exhibition. Similarly, production processes in the third millennium BC are discussed alongside reception processes in the Hellenistic period, Medieval Islamic period, and the third millennium AD. I make the deliberate choice of concentrating largely on rarely discussed topics ranging from the exhibition contexts in the Ottoman Imperial Museum to the intersections of Mesopotamian archaeology with the politics of land tenure and related regulations; from the text-image dialectic in Sumerian art to phenomenological modes of visualization; or from the Medieval Islamic engagement with Tello and the statues of Gudea to the local and international networks of looting that have largely remained intact since the second half of the nineteenth century. All in all, I argue for a radical change in perspective in our engagements with pasts, presents, and futures, and contend that this change is not merely a matter of historiographical accuracy: it both informs our understanding of ancient contexts and constitutes an ethical position to address various burning issues in art history and archaeology today, including the restitution and repatriation of antiquities and the decolonization of the field.