Background and Context:
Abimelech, a son of Gideon (also known as Jerubbaal), is a significant figure in the Book of Judges. His account is primarily found in Judges 9. Gideon, a judge of Israel, had many sons, and Abimelech was born to his concubine in Shechem. After Gideon's death, Abimelech sought to establish himself as ruler over Shechem and eventually over Israel, leading to a series of violent and treacherous events.

The Conspiracy:
Abimelech's conspiracy begins with his ambition to rule. He approached the leaders of Shechem, his maternal relatives, to support his claim to leadership. He argued that it would be better for them to be ruled by one man, himself, rather than by the seventy sons of Gideon. Abimelech's appeal to familial ties and his promise of shared power persuaded the leaders of Shechem.

Judges 9:1-3 :
"Now Abimelech son of Jerubbaal went to his mother’s brothers at Shechem and said to them and to the whole clan of his mother, 'Please ask all the leaders of Shechem, "Is it better for you that seventy men, all the sons of Jerubbaal, rule over you, or just one man? Remember that I am your own flesh and blood."' And his mother’s brothers spoke all these words on his behalf in the presence of all the leaders of Shechem, and they were inclined to follow Abimelech, for they said, 'He is our brother.'"

Funding and Execution:
With the support of the Shechemites, Abimelech received seventy shekels of silver from the temple of Baal-berith. He used this money to hire reckless and worthless men who became his followers. Abimelech then went to his father's house in Ophrah and killed his seventy brothers, the sons of Gideon, on one stone, sparing only the youngest, Jotham, who managed to hide.

Judges 9:4-5 :
"They gave him seventy shekels of silver from the temple of Baal-berith, and with this Abimelech hired worthless and reckless men, who followed him. He went to his father’s house in Ophrah and killed his brothers, the seventy sons of Jerubbaal, on one stone. But Jotham, the youngest son of Jerubbaal, survived, because he hid himself."

Jotham's Parable:
After the massacre, Abimelech was made king by the leaders of Shechem and Beth-millo. Jotham, the surviving son of Gideon, stood on Mount Gerizim and delivered a parable to the people of Shechem, warning them of the consequences of their actions. He likened Abimelech to a bramble, a worthless plant, and foretold that fire would come from Abimelech to consume the leaders of Shechem and vice versa.

Judges 9:7-15 :
"When this was reported to Jotham, he climbed to the top of Mount Gerizim, raised his voice, and called out to them: 'Listen to me, O leaders of Shechem, and may God listen to you. One day the trees set out to anoint a king over themselves. They said to the olive tree, "Reign over us." But the olive tree replied, "Should I stop giving my oil that honors both God and man, to hold sway over the trees?" Then the trees said to the fig tree, "Come and reign over us." But the fig tree replied, "Should I stop giving my sweetness and my good fruit, to hold sway over the trees?" Then the trees said to the vine, "Come and reign over us." But the vine replied, "Should I stop giving my wine that cheers both God and man, to hold sway over the trees?" Finally all the trees said to the thornbush, "Come and reign over us." But the thornbush replied, "If you really are anointing me as king over you, come and find refuge in my shade. But if not, may fire come from the thornbush and consume the cedars of Lebanon!"'"

The Downfall:
Jotham's curse eventually came to pass. God sent an evil spirit between Abimelech and the leaders of Shechem, leading to mutual distrust and conflict. The leaders of Shechem rebelled against Abimelech, and a series of battles ensued. Abimelech destroyed Shechem and sowed it with salt. However, his reign ended when he attacked the city of Thebez. During the siege, a woman dropped a millstone from a tower, fatally injuring him. To avoid the disgrace of being killed by a woman, Abimelech ordered his armor-bearer to kill him.

Judges 9:56-57 :
"In this way God repaid the wickedness that Abimelech had done to his father by murdering his seventy brothers. And God also brought all the wickedness of the men of Shechem back upon their heads, and upon them came the curse of Jotham son of Jerubbaal."

Significance:
Abimelech's conspiracy and its aftermath serve as a cautionary tale about the dangers of ambition, betrayal, and the consequences of turning away from God. The narrative highlights the themes of divine justice and retribution, as well as the instability that arises from unrighteous leadership.