Like the exchange of messengers, the exchange of gifts between kings was a sign of good relations. Even if it wasn't a question of trade, it was implicitly understood that a gift from one king implied a counter-gift from his counterpart, and of a value deemed equivalent. However, gifts played a particularly important role when alliances were being formed. In Paleo-Babylonian times, the death of a king was a crucial moment, since the alliances he had concluded automatically came to an end. Before calling upon his successor, the other kings began by sending gifts for the burial of the deceased king. They would then send gifts to the new sovereign, accompanied by a proposal of alliance. These gifts are sometimes listed in letters, and can also be found in accounting documents. In some cases, the amount of "regular gifts" was fixed by agreement between the kings at the very moment of concluding their alliance: this is known as "tribute".
When kings entered into an alliance, it was often extended by a dynastic marriage, with one king giving the other one of his daughters - usually to marry one of his sons. Such dynastic marriages are known throughout the three millennia of Mesopotamian history, and practices seem to have changed little over this long period.
