The land of Assyria itself encompassed what is today the northern half of modern Iraq, north-east Syria, south-east Turkey and the north-western fringe of Iran. During the mid 11th to late 10th century BCE Assyria was pressed on all sides by tribal and mountain peoples, including Aramean tribes at times occupying Tur Abdin, Nisibin and the Khabur Delta in the north-eastern Levant, areas long considered to be integral parts of Assyria itself. Thus Assyria had difficulty keeping its trade routes open, and its borders were constantly threatened by tribal peoples.[citation needed]