Even after 245 years of fighting, it seemed that people still had not learned that Delphi would always defend itself against invasion and desecrations. Just 7 years after the last war has ended, a new threat emerged on the southern plain of the City in 339 BCE, as the City of Amphissa (a region of Phocis) began to take possession of and cultivate the sacred land of Apollon that was always supposed to remain untouched without exception. It belonged exclusively to the God.
Delphi was a beautiful place of architectural and dedicatory advancement during this period. Its previous wars and the great conflicts between the Cities involved had not inflicted any damage on its religious functions or the love and devotion that people continued to retain for this center of their world. In fact, most Cities had an interest in protecting it, but religious and diplomatic unrest seems to have always been a danger from those who felt they had to compete.
After Philip II had won the last Sacred War for Delphi in 346 BCE, an agreement of peace between the parties had keep confrontation rather lowkey. That was until the people of Amphissa, or at least their government, came into the picture. It does not appear that there was a cease and desist order for uprooting Apollon's land, and it could be argued that even if there had been, the League of Delphi would have sought punishment for the offense. Amphissa was to face a military conquest by the Delphic Forces.
Philip was naturally chosen to lead the assault, but his mentality and strategy seems to have been different this time. It appears that Phillip viewed the Fourth Sacred War as the war to end all Sacred Wars. Not only did he plan to defeat Amphissa, but conquer all of Greece itself in order to bring stability amid the Wars. He successfully invaded the City, exiled all of its citizens, and allowed Delphi to take control of it. And by 336 BCE, all of Greece would come under Phillip's authority. Although he was not universally opposed by mainland Greeks. The Cities of Thessaly, Argos and Arkadia fought on his side, while various other States led by the great powers of Athens and Thebes fought against them. The armies of both Athens and Thebes were decimated at the Battle of Chaeronea, which brought the war to its official close. As a result, the Hellenic League or League of Korinth came into being, consisting of the united City States that would later be used in the Eastern campaigns of Macedon.
Phillip may have conquered the Greeks, but in reality, he was not that much different from them. He worshiped the Greek Gods and lived by Greek culture, as would his successor. While Phillip was viewed by many as the Lord of the peace that had been absent for so long, it also made him a target for those still determined to resist and/or who had major problems with him. Only 2 years after his ultimate victory, Phillip was assassinated. His son, Alexander the Great, became the king of a united Greece in a final overthrow of the Persian Empire, which he achieved. But Alexander would also die only 13 years later, and His Empire divided among His generals.
It appears that Phillip and Alexander, who fought alongside His father in the Delphic Wars, had achieved their goal, as there were no more Sacred Wars of Delphi. The only other conflict that came to be termed a Sacred War was actually a conflict between Alexander's generals after His death over control of the regions of the Empire. While Delphi was, of course, included in the Empire, it was no longer specifically about them.
In the Goodness of the Gods,
* Scott, Michael, Delphi: A History of the Center of the Ancient World, Princeton Publishing, 2014.