ORGANISATION AND LOGISTICS OF EARLY TRADING
RELATIONS
The presence of Dilmun tax-collectors from as early as the Late Uruk period suggests
state intervention (taxation) in a trading context from the very start of the observable
relationship. This in turn implies the existence in Mesopotamia of mercantile concerns
operating independently of the central state. This does not rule out the parallel
existence of state-sponsored trading expeditions: the protoliterate economic tablets,
with their record of disbursements of grain, wool or textiles and milk products to
individuals connected in some way with Dilmun, may constitute evidence that the
Uruk state underwrote trading expeditions to the Gulf. If not from a state or palace
archive, these tablets could alternatively constitute the records of temples or private
estates. Isolated scraps of evidence from the Central Gulf and the Oman Peninsula (the
bulla, and the seal from Madinat Zayed) imply that individuals from Mesopotamia
were present in both areas, though it is unknown what public or private organisations
they represented. It is also unknown whether such individuals operated as isolated
agents in an entirely foreign milieu in the Gulf, or whether trading colonies were
founded there in the manner of the northern Uruk Expansion.
It appears that the search for copper and other raw materials was a major motive
behind the movement of these early explorers (and perhaps settlers). In terms of
journey times, a supply of copper from the Gulf region was almost certainly more easily
accessed than the older sources in Anatolia and Iran. It is not coincidental that the
northwards Uruk Expansion tailed off at the same time that southern Mesopotamian
trading interests reactivated in the Gulf, a point that has been noted before (D.T. Potts
1990 : 92 ). Although some believe that Uruk interests in the north were terminated by
a phase of socio-environmental collapse in the south, leading to the weakening of
communication with the colonies and ultimately the expulsion of southern colonists
by resurgent local communities (Algaze 1993 : 105 – 107 ), others see no evidence for such
disruption in the south (Nissen 2001 : 166 – 167 ). Instead, the southern population may
have switched its trading interests to the Gulf region because the relative efficiency of
maritime transport within the Gulf, compared to riverine transport up the Euphrates
and Tigris.
To take a specific example, a journey up the Euphrates from Uruk to the Late Uruk
trading depot at Hacınebi was around 1360 km, following the course of the river.
According to Salonen, ancient river boats on the Euphrates had to be towed upstream
by teams of men, with speeds varying between 10 km and 20 km per day depending
on the size of the towing team, and presumably the size of the boat (Casson 1995 : 29 ).
Assuming no rest days, journeys would therefore have taken between 68 and 136 days.
The return was faster, with downstream speeds of 30 – 35 km per day, giving a time of
approximately thirty-nine days. The entire return journey time would therefore have
been between approximately 175 and 107 days – somewhere between three-and-a-half
and six months, assuming no breaks on the way.
In contrast, maritime transport between the southern Mesopotamian sites and the
Central and Lower Gulf was considerably quicker. Estimates of average speed on
traditional craft vary from about 4 knots/ 7. 4 km per hour or faster (for Roman trading
craft in the Mediterranean) to an average of about 1. 75 knots/ 3. 24 km per hour
(Johnstone 1980 : 81 – 82 ; Vosmer 2003 : 157 , note 1 ). Assuming a coast-hugging route,
the distance between Ur and Umm an-Nar island, the assumed terminus of the copper
–– The Sumerians and the Gulf ––