Complex sentence: On 1 November attacks by the ANZAC Mounted Division towards Tel el Khuweilfe and the road to Hebron and Jerusalem concerned the Ottoman defenders, who feared that a major cavalry attack could break the Ottoman line and capture the Seventh Army headquarters at Hebron.
Split into simpler sentences: On 1 November, strong attacks by the Anzac Mounted Division towards Tel el Khuweilfe and the road to Hebron and Jerusalem, gravely concerned the Ottoman defenders. They feared a major cavalry attack could break the Ottoman line, and capture the headquarters of the Seventh Army at Hebron.