THAT particular style of church IS actually original to the Catholic Church. It IS Christian in origin - though inspired, sure, by it's preceding Roman and Greek building. The centralized, squared Greek-cross style which transitions to a dome overhead was first constructed in Constantinople by the CATHOLIC CHURCH and is called the Hagia Sophia.
Only YEARS LATER was it (the Hagia Sophia) converted into a Mosque at which time minarets and other Islamic elements were added.
But the original design was commissioned by Justinian in 532 AD - two Greek mathematicians (Anthemius of Tralles and Isidorus of Miletus) planned the Hagia Sophia which is unique in the way that the dome sits atop one large, open cube - 4 large rounded arches (which are Greek in origin) sculpt the architectural element called 'pendentives' in the corners, visible from the inside. From the outside it merely takes on a massive, bold cube-shape.
All these people thinking it *is a Islamic design* are showing their ignorance of their own beliefs they claim to have - and obviously have peeved me of with their stupidity on the subject.
That being said, however - yes, many elements of Islamic architecture were introduced into the European religious world during the time of the crusades - likewise, they adopted some European designs and ideas in their religious-mosques (like how they converted the Hagia Sophia into a Mosque according to their religious-dictation, which involved covering over hte original mosaics and removing countless sculptures from the inside).
Fortunately the interior of the Hagia Sophia is being restored to it's original form - uncovering the mosaics of Justinian and his wife.
