An article of footwear incorporating a sole structure, the sole structure comprising: a midsole that includes a fluid-filled chamber, the fluid-filled chamber comprising: an outer barrier defining an interior void, a tensile structure (50a, 50b) located within the interior void and bonded to the outer barrier, a peripheral edge that extends around a periphery of the chamber, and a window portion located around at least part of a periphery of the tensile structure (50a, 50b), the window portion having a first area with a first extent of outward protrusion and a second area with a second extent of outward protrusion, the first extent of outward protrusion exceeding the second extent of outward protrusion, such that the peripheral edge is spaced from the tensile structure (50a, 50b) by a first distance in the first area and by a second distance in the second area, the first distance being greater than the second distance; and an outsole secured to the midsole, the outsole forming at least part of a ground-contacting surface of the footwear, wherein the tensile structure (50a, 50b) has a first height at a first part adjacent to the first area and a second height at a second part adjacent to the second area, the first height being substantially the same as the second height. a midsole that includes a fluid-filled chamber, the fluid-filled chamber comprising: an outer barrier defining an interior void, a tensile structure (50a, 50b) located within the interior void and bonded to the outer barrier, a peripheral edge that extends around a periphery of the chamber, and a window portion located around at least part of a periphery of the tensile structure (50a, 50b), the window portion having a first area with a first extent of outward protrusion and a second area with a second extent of outward protrusion, the first extent of outward protrusion exceeding the second extent of outward protrusion, such that the peripheral edge is spaced from the tensile structure (50a, 50b) by a first distance in the first area and by a second distance in the second area, the first distance being greater than the second distance; and an outsole secured to the midsole, the outsole forming at least part of a ground-contacting surface of the footwear, an outer barrier defining an interior void, a tensile structure (50a, 50b) located within the interior void and bonded to the outer barrier, a peripheral edge that extends around a periphery of the chamber, and a window portion located around at least part of a periphery of the tensile structure (50a, 50b), the window portion having a first area with a first extent of outward protrusion and a second area with a second extent of outward protrusion, the first extent of outward protrusion exceeding the second extent of outward protrusion, such that the peripheral edge is spaced from the tensile structure (50a, 50b) by a first distance in the first area and by a second distance in the second area, the first distance being greater than the second distance; and an outsole secured to the midsole, the outsole forming at least part of a ground-contacting surface of the footwear, wherein the tensile structure (50a, 50b) has a first height at a first part adjacent to the first area and a second height at a second part adjacent to the second area, the first height being substantially the same as the second height.