Seleucus established a cohesive Central Asian policy, which "went beyond the limited, ad hoc military and political aims of Alexander", according to historian Frank Holt. After the Seleucid–Mauryan war, Seleucus ceded the Indus Valley to Chandragupta Maurya, in return for a pact of friendship and 500 war elephants; he thus sought the sustained economic and military development of Bactria, which was now the headquarters of the Seleucids in the East. Antiochus, who had a personal connection to the region through his mother, Apama, the daughter of the Sogdian warlord Spitamenes, continued the policies of his father. Several of Ai-Khanoum's key buildings, including the heroön (hero's shrine), the northern fortifications, and a shrine, were constructed under his reign. It is likely that a mint was opened in Ai-Khanoum in around 285 BC, both because of the metal deposits near the city and a growing Seleucid interest in eastern Bactria, which suggests that this mint spurred the growth of the city as a royal foundation. Around one-third of the bronze coins found in the city were issued in the period following Antiochus' accession in 281 BC, an indication that he continued to spend money on the city. Under his successor Antiochus II, who came to the throne in 261 BC, the mint continued to strike valuable coins, and the ramparts were bolstered with a buttress and brick linings. The city's development was greatly slowed when Diodotus I, governor of the eastern provinces, seceded from the Seleucids and founded the Greco-Bactrian Kingdom. Although Ai-Khanoum's temple and sanctuary were reconstructed under Diodotus, possibly to enhance religious legitimacy, most Seleucid construction programmes were not continued. Bertille Lyonnet theorises that during this time Ai-Khanoum was merely "a military stronghold with administrative functions". The Seleucid emperor Antiochus III invaded the Greco-Bactrian Kingdom in 209 BC, defeating its ruler Euthydemus I at the Battle of the Arius and unsuccessfully besieging Bactra, Euthydemus' capital. Although there is no evidence that Ai-Khanoum was itself attacked by the invaders, Antiochus may have conducted operations near the city, or even minted his currency there. He may have also brought new settlers to the region. The later conquests of Euthydemus and his successor Demetrius I were also beneficial for the city, as the population increased and many public buildings were reconstructed. The improvement in the city's fortunes can be seen through innovations in the manufacturing and sophistication of pottery—Achaemenid styles were replaced with