The early books of maghāzī include accounts of events which are not military expeditions, such as the treaty-making at Hudaybiyah, the Prophet's last pilgrimage. In terms of form as well as theme, maghāzī literature is superficially reminiscent of the pre-Islamic accounts of tribal battles: both deal with battles and are an mélange of prose and verse. Urwah b. al-Zubayr was the first to classify the material on the maghāzī. His importance as an early architect of the maghāzī literature is confirmed by the frequency of the citations from him in the later authorities such as Ibn Ishaq, Musa b. Uqbah, and al-Wāqidī. The handling of the battle of Badr illustrates characteristics more broadly representative of their individual works. Al-Wāqidī's version of Badr is still the best-knit and contains much incidental material of great historical interest, such as the details of the Meccans' investment in the caravan ambushed at Badr.