Horus was one of the most significant Egyptian deities who served many functions, most notably the god of kingship and the sky.
Conflict with Set
Set wanted the throne of Egypt, which belonged to his brother, Osiris. Set murdered Osiris to gain his throne. The method of this murder differs depending on the source of the story. Most Egyptian copies just say that Set drowned Osiris. The Greco-Roman copies are much more elaborate. They begin with Set building a sarcophagus that fitted Osiris exactly.
Then Set tricked his brother into getting inside the sarcophagus. He then sealed the coffin and threw it into the Nile. Isis recovered Osiris’ body but Set stopped her before she could restore her husband to life. Set then cut up Osiris’ body and spread the pieces throughout Egypt. Isis and her sister Nephthys recovered all the pieces of Osiris’ body but one, which a fish ate. Isis managed to bring Osiris back for one night during which she conceived Horus the Younger. She hid Horus from Set while he was growing into adulthood. Set tried to kill Horus while he was a boy but the attempts failed.
When Horus grew up, he fought Set to avenge his father. The conflict lasted for decades. Finally, Set turned into a hippopotamus and tried to destroy Horus’ boat. Horus speared Set but the other gods stopped him from destroying his uncle. This was how Horus avenged Osiris’ murder and gained the throne of Egypt.