Iran–Iraq border
The Iran–Iraq boundary runs for 1,458 kilometers, from the Shatt al-Arab (known as Arvand Rud in Iran) waterway to the tripoint boundary with modern Turkey at the Kuh e-Dalanper. Although the boundary was first determined in 1639, certain disputes fester, particularly disputes surrounding navigation on the Shatt al-Arab waterway.
The boundary begins in the Persian Gulf at the "lowest point of low water" at the mouth of the Shatt al-Arab at 29°51′16″N 48°44′45″E / 29.85444°N 48.74583°E (WGS84.) It then closely follows the thalweg of the Shatt al-Arab for some 105 km in a series of short straight line segments, reaching the confluence of the Shatt al-Arab and the Nahr al-Khayin tributary. From there, it winds northward, following a series of boundary markers across plain and hill, through the Zagros Mountains Nahr at-Tib, and Nahr Wadi. It meets the boundary with Turkey at 37° 08' 44" N and 44° 47' 05" E.
The boundary dates back to the 1639 Zuhab Treaty between the Ottoman Empire, which controlled Iraq, and Persia. The agreement stipulated that the boundary would run between the Zagros Mountains and the Tigris River. In 1724, the Ottomans rejected the boundary-line and invaded Persia, but when peace was finally concluded in 1746, the two states recognized the 1639 boundary as official. That was affirmed by the 1847 Treaty of Erzerum, but the new treaty first raised the issue of the Shatt al-Arab waterway. The boundary was set at the eastern bank of the Persian gulf so that the entire waterway remained under Turkish (Iraqi) control. In the following years, the boundary-line was further delineated, and a detailed map was produced in 1860.
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