After laying seige to the powerful Byzantine city for 53 days, the Ottoman's were able to capture this powerful capital. Not only was this city an important symbol for Eastern Christianity, but it sat in the middle of a trade network connecting Europe to Asia. This event also showed the importance of a relatively new invention, gunpowder, since it was essential in the Ottoman Victory. Further more, the Ottoman's used the victory to their advantage by instituting a "devshirme" or tribute on Christians in the area. They allowed Christians to remain and worship as they please, as long as they donated a group of young men to the Ottoman's. These young men were converted to Islam and were called Janissaries. Most served in the army, but some made up the bureaucracy of the Ottoman empire, which further allowed for the expansion.