Conquering Constantinople no easy task for Muhammad, as Constantinople had withstood many sieges and attacks over the centuries because of its formidable defences. Even Muslims of the past tried and failed to do so. The Byzantine capital was positioned by the sea making it tremendously difficult to attack and its naval fleet didn’t make things any easier for the opposing forces. The Byzantines had a secret weapon known as ‘Greek Fire’, a highly flammable liquid that was used in naval engagements where it would instantaneously set ships ablaze and it could not be put out by water. (Cartwright and Cartwright, 2017).