Complex sentence: The 1967 siege of Sana'a became the turning point of the war-the remaining republican Prime Minister succeeded in keeping control of Sana'a and by February 1968, the royalists lifted the siege.
Split into simpler sentences: The 1967 siege of Sana'a became the turning point of the war. The remaining republican Prime Minister succeeded in keeping control of Sana'a and by February 1968, the royalists lifted the siege.