window.dotcom = window.dotcom || { cmd: [] }; window.dotcom.ads = window.dotcom.ads || { resolves: {enabled: [], getAdTag: []}, enabled: () => new Promise(r => window.dotcom.ads.resolves.enabled.push(r)), getAdTag: () => new Promise(r => window.dotcom.ads.resolves.getAdTag.push(r)) }; setTimeout(() => { if(window.dotcom.ads.resolves){ window.dotcom.ads.resolves.enabled.forEach(r => r(false)); window.dotcom.ads.resolves.getAdTag.forEach(r => r("")); window.dotcom.ads.enabled = () => new Promise(r => r(false)); window.dotcom.ads.getAdTag = () => new Promise(r => r("")); console.error("NGAS load timeout"); } }, 5000)

The fortress at the heart of 'bloodiest siege in history'

The Knights Hospitaller, defenders of the Holy Land and protector of pilgrims, were searching for a new home following the invasion of Jerusalem.

The Holy Roman Emperor agreed to help, supplying them with a new base, providing two conditions were met.

Watch the full documentary on BBC Select