A fenestrated graft deployment system, with a delivery catheter having a catheter body, a first fenestration alignment device, and an endoluminal prosthesis having a main graft body having a lumen therethrough and a first opening laterally therein. The first fenestration alignment device is configured to extend through at least a portion of the delivery catheter and is configured to be axially moveable relative to the first guidewire. The first fenestration alignment device can cause the main graft body adjacent to the first opening to move with the end of the first fenestration alignment device to allow an operator to align the first opening in the side of the endoluminal prosthesis with an ostium of a target branch vessel into which said first opening is to extend and act as a guide and seal for a subsequently delivered branch graft endoluminal prosthesis.
