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| 1917, May 5–19 |
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| Battle of the Vardar (or Doiran). These engagements were inconclusive but served to convince the Allied powers that success on this front hinged on the Athens government. | 1 |
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| June 11–12 |
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| The newly arrived French envoy (Charles Jonnart) presented an Allied ultimatum, demanding the abdication of King Constantine and the renunciation of the claims of the Greek crown prince. At the same time Allied troops invaded Thessaly and a French force occupied the Isthmus of Corinth. | 2 |
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| June 12 |
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| Constantine abdicated in favor of his second son, Alexander. | 3 |
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| June 26 |
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| Venizelos became premier, replacing Zaimis. | 4 |
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| June 27 |
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| The Greek government severed relations with the Central powers and entered the war on the Allied side. | 5 |
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