Keywords: Ancient Near East, Hittite Empire, Assyria, Middle Assyrian kingdom, war, conflict. This article addresses the complicated issues of Hittite-Assyrian relations and military conflicts from the second half of Middle Assyrian period (ca. 1365–1180 BCE) until the fall of the Hittite Empire (ca. 1180 BCE). The article is based on the analysis of Akkadian and Hittite cuneiform texts. We have some historical records (cuneiform texts) like treaties, letters, legal documents, etc., which show quite clearly the relations between the kings of Hatti and Assyria. The key events of these relations are mentioned in Hittite-Assyrian international correspondence (diplomatic letters), royal inscriptions, and annals. The article aims to reconstruct possible Hittite-Assyrian relations at the end of the Late Bronze Age on the basis of remaining written sources from this period. This is of course only a hypothetical image or mosaic that was proposed by the author; other reconstructions and hypotheses are also possible. In this article, some issues related to the establishment of the power of the Middle Assyrian kingdom during the fourteenth to thirteenth centuries BCE, and at the beginning of Assyrian expansion into northern Mesopotamian and North Syrian regions. These events caused several Hittite-Assyrian diplomatic crises and military conflicts and even wars between these two superpowers of the Late Bronze Age, during the thirteenth century. It seems that Assyrian-Hittite wars and military conflicts had begun already at the beginning of the first decades of the thirteenth century BCE, when Assyrian kings, including Adadnarari I and Salmanassar I, conquered and destroyed the powerful kingdom of Khanigalbat, which belonged to the Hurrians and had been for several years a satellite state of the Hittites. Before this event Khanigalbat was partly conquered by the Hittite king Suppiluliuma I in the fourteenth century BCE. The aim of this state (it was turned into a vassal state) was to be a zone for protection of the Hittite empire’s territories from possible foreign invasions from southern and northern Mesopotamia. During the thirteenth century, Assyrians destroyed the remains of the kingdom of Khanigalbat (Mitanni), conquered it, and the Middle Assyrian kingdom got a border with the powerful Hittite empire, which controlled Anatolia and North Syria. This became the reason for many diplomatic and military conflicts between these two great powers during the thirteenth century BCE, until the Middle Assyrian kingdom weakened after the death of despotic Assyrian king Tukulti-Ninurta (1242–1206 BCE). At the same time, the weakened Hittite empire collapsed – it was conquered by invaders from the Aegean region, so-called “Sea Peoples”. This event took place in ca. 1190–1180 BCE. Struggles and conflicts between the Hittite empire and the Middle Assyrian kingdom during the thirteenth century BCE were partly documented (international correspondence, royal inscriptions, etc.), but there are not enough written sources from this period and this is a serious issue for reconstruction of Hittite-Assyrian relations. These relations were not strictly hostile, as we know from records that some of the period’s Assyrian and Hittite kings communicated as equal and probably friendly partners. There was also active trade and other relations (diplomatic, dynastic, etc.) between the Hittites and Assyrians. Vladimir Sazonov (b. 1979) is an Associate Professor at the Estonian National Defence College and a Senior Researcher at the Centre for Oriental Studies, University of Tartu.