Baalshamin or Ba'al Šamem (Aramaic: ܒܥܠ ܫܡܝܢ), lit. 'Lord of Heaven(s)', was a Northwest Semitic god and a title applied to different gods at different places or times in ancient Middle Eastern inscriptions, especially in Canaan/Phoenicia and Syria. The title was most often applied to Hadad, who is also often titled just Ba‘al. Baalshamin was one of the two supreme gods and the sky god of pre-Islamic Palmyra in ancient Syria (Bel being the other supreme god). There his attributes were the eagle and the lightning bolt, and he perhaps formed a triad with the lunar god Aglibol and the sun god Malakbel.
Baalshamin and Ba'al Šamem are the most frequently used terms, as a Syrian god and as a Phoenician god, respectively. Other variations which are seen less frequently in modern sources include: Ba'al Shamin, Ba'al Samin, Ba'al-Shamem, Ba'al Shamim, Baal Shamem, Ba'alsamem, Baal Shamin, Baal-Samin, Beelsamen, Ba'alsamin, Baal-Samen, Baal-Shamen, Baalsamin, Baalsamen, Baal-shamim, Ba'alshamin, Baal-Samim, Baal-Samem, Baalsamem, Baalsamim, Baalshamem, Beelsamin, Beel-Samen, Beelshamen, Baal-Shamayim, Ba'alsamen, Beel-Samin, Baalshamim, Baalshamen.
This name was originally a title of Baal Hadad, in the 2nd millennium BC, but came to designate a distinct god circa 1000 BC. The earliest known mention of this god or title is in a treaty of the 14th century BC between Suppiluliumas I, King of the Hittites, and Niqmaddu II, King of Ugarit. Although this could be a reference to Baal Hadad, and again when the name appears in a Phoenician inscription by King Yeḥimilk of Byblos, other texts make a distinction between the two.
In the treaty of 677 BC between King Esarhaddon of Assyria and King Ba‘al I of Tyre, a curse is laid against King Baal if he breaks the treaty, reading in part: