An endovascular stent graft comprising: a. a main tubular body of a biocompatible graft material having a proximal end portion and a distal end portion and a lumen extending between the proximal and distal end portions; b. a first leg (14,16) defining a first lumen and a second leg (14,16) defining a second lumen, the first and second legs (14,16) extending from the distal end portion of the main tubular body and wherein the first and second lumens are in fluid communication with the lumen of the main tubular body; the first and second legs (14,16) each having an internal surface and an external surface and wherein the respective internal surfaces of the first and second legs (14,16) are adjacent; and, c. a first fenestration (40,48) formed in each of the first and second adjacent internal surfaces, and wherein the respective first fenestrations (40,48) at least partially align with each other; d. a side branch extending from at least one of the first and second legs(14,16), the side branch comprising a tubular body of a biocompatible graft material having a proximal end portion and a distal end portion and a lumen extending between the proximal and distal end portions, the side branch lumen being in fluid communication with the lumen of the at least one of the first and second legs (14,16) from which it extends; e. wherein the proximal end portion of the side branch extends from the at least one of the first and second legs (14,16) at a location that is substantially adjacent to the first fenestration (40,48); and f. whereby the stent graft is configured to be deployed into the vasculature of a patient with at least one of the first and second legs (14,16) being located in the common iliac artery and the side branch being directed towards an internal iliac artery of the common iliac artery. a. a main tubular body of a biocompatible graft material having a proximal end portion and a distal end portion and a lumen extending between the proximal and distal end portions; b. a first leg (14,16) defining a first lumen and a second leg (14,16) defining a second lumen, the first and second legs (14,16) extending from the distal end portion of the main tubular body and wherein the first and second lumens are in fluid communication with the lumen of the main tubular body; the first and second legs (14,16) each having an internal surface and an external surface and wherein the respective internal surfaces of the first and second legs (14,16) are adjacent; and, c. a first fenestration (40,48) formed in each of the first and second adjacent internal surfaces, and wherein the respective first fenestrations (40,48) at least partially align with each other; d. a side branch extending from at least one of the first and second legs(14,16), the side branch comprising a tubular body of a biocompatible graft material having a proximal end portion and a distal end portion and a lumen extending between the proximal and distal end portions, the side branch lumen being in fluid communication with the lumen of the at least one of the first and second legs (14,16) from which it extends; e. wherein the proximal end portion of the side branch extends from the at least one of the first and second legs (14,16) at a location that is substantially adjacent to the first fenestration (40,48); and f. whereby the stent graft is configured to be deployed into the vasculature of a patient with at least one of the first and second legs (14,16) being located in the common iliac artery and the side branch being directed towards an internal iliac artery of the common iliac artery.