Semitic people
Astarte arrived in ancient Egypt during the 18th dynasty along with other deities who were worshipped by northwest Semitic people, namely Anat, Baal (conflated with Set, who as a result started to be viewed as a heroic "foreign" god), Horon, Reshef and the enigmatic Qudshu. Due to her nature of a warrior goddess, often paired with Anat, Astarte was associated with warfare in Egyptian religion too, especially with horses and chariots. Due to late arrival of these animals in Egypt, they weren't associated with any native deity prior to her introduction.