Short answers, pulled from the story.
Palmyra is an ancient city in central Syria, located 215 km northeast of Damascus in an oasis on the edge of the Syrian Desert. Its ancient Semitic name, Tadmor, is also the name of the modern village that sits adjacent to the archaeological site; residents were relocated there in 1932 during the French Mandate period.
Zenobia was the queen regent of Palmyra who ruled as de facto leader after her husband Odaenathus was assassinated in 267 AD. She conquered Roman Arabia in 270, invaded and won Egypt that same year, and pushed Palmyrene forces through Anatolia as far as Ankara by 271. Roman emperor Aurelian defeated her at the Battle of Immae and again at the Battle of Emesa, capturing her after she fled toward Persia.
Islamic State militants destroyed the Temple of Baalshamin on the 23rd of August 2015, the cella of the Temple of Bel on the 30th of August 2015, three major tower tombs including the Tower of Elahbel on the 4th of September 2015, and the Arch of Triumph using dynamite in October 2015. In January 2017 they destroyed the tetrapylon and part of the Roman theatre. The antiquities chief Khaled al-Asaad was beheaded on the 18th of August 2015 after refusing to reveal where the city's treasures were hidden.
Odaenathus was a Palmyrene leader who held the title of exarchos of Palmyra from at least 252 AD. After the Roman emperor Valerian was captured by the Persians at the Battle of Edessa in 260, Odaenathus assembled an army and defeated the Persians near the Euphrates, drove them from Roman Mesopotamia, and twice besieged the Persian capital Ctesiphon. The emperor Gallienus awarded him the title Imperator Totius Orientis and he assumed the title King of Kings. He was assassinated in 267 along with his son Hairan I.
Palmyrenes spoke Palmyrene Aramaic, a variety of Western Middle Aramaic, as their primary language and used a distinctive Palmyrene alphabet until the late third century AD. Wealthier inhabitants used Koine Greek for commercial and diplomatic purposes, and Greek became dominant during the Byzantine era. After the Arab conquest in the seventh century, Arabic replaced Greek, and a local Palmyrene dialect of Arabic eventually evolved.
Palmyra's trade wealth grew through two developments in the first and second centuries AD. Palmyrene merchants built and garrisoned their own caravan routes, including a garrison at Dura-Europos manned in 117 AD. Rome's conquest of the Nabataean capital Petra in 106 AD shifted control of the Arabian Peninsula's southern trade routes away from the Nabataeans and directed them through Palmyra. The city established merchant colonies along the Silk Road and throughout the Roman Empire.