Delphi
In 356 BC the Phocians under Philomelos captured and sacked Delphi, leading to the Third Sacred War (356–346 BC), which ended with the defeat of the former and the rise of Macedon under the reign of Philip II. This led to the Fourth Sacred War (339 BC), which culminated in the Battle of Chaeronea (338 BC) and the establishment of Macedonian rule over Greece.
In Delphi, Macedonian rule was superseded by the Aetolians in 279 BC, when a Gallic invasion was repelled, and by the Romans in 191 BC. The site was sacked by Lucius Cornelius Sulla in 86 BC, during the Mithridatic Wars, and by Nero in 66 AD. Although subsequent Roman emperors of the Flavian dynasty contributed towards to the restoration of the site, it gradually lost importance. In the course of the 3rd century mystery cults became more popular than the traditional Greek pantheon. Christianity, which started as yet one more mystery cult, soon gained ground, and this eventually resulted in the persecution of pagans in the late Roman Empire. The anti-pagan legislation of the Flavian dynasty deprived ancient sanctuaries of their assets. The emperor Julian attempted to reverse this religious climate, yet his "pagan revival" was particularly short-lived. When the doctor Oreibasius visited the oracle of Delphi, in order to question the fate of paganism,he received a pessimistic answer:
Third Sacred War
The destruction of the Phocian cities and the heavy fine imposed on the Phocian confederation certainly caused the Phocians to bear a grudge against Philip II. Seven years later the Locrians brought charges against the Athenians in the amphictyonic council and a special session of the council was set in order to deal with that matter. The Athenians, however, did not send envoys and neither did the Thebans. This was a clear insult to the council and Philip II intervened once more as a regulator. The Fourth Sacred War broke out, ending in the total subjugation of Greece to the kingdom of Macedonia. The Phocians recovered gradually from the repercussions of the Third Sacred War and managed to be reinstated in the Amphictyony in 279 BC, when they joined forces with the Aetolian League fighting against the Gauls. 
However, a serious side-loss of the Third Sacred War remained the destruction of a large number of ex votos and other precious offerings to the sanctuary of Apollo, which deprived not only the sanctuary itself but also the later generations of some magnificent pieces of art.