A gas turbine (400; 500; 700) comprising: a high pressure spool (410; 582; 710); a high pressure compressor (402; 580; 702) mechanically coupled to the high pressure spool; a high pressure turbine (406; 604; 706) mechanically coupled to the high pressure spool (410; 582; 710); a lower pressure spool (422; 558; 722); and a lower pressure turbine (420; 608; 720) mechanically coupled to the lower pressure spool (422; 558; 722); a fan (424; 550; 724) having a first set of fan blades (426; 552; 726) and a second set of fan blades (430; 554; 730), the second set of fan blades (430; 554; 730) being located downstream of the first set of fan blades (426; 552; 726) and being operative to rotate at a rotational speed corresponding to a rotational speed of the lower pressure spool (422; 558; 722); a first gear assembly (428; 560; 728) mechanically coupled to the lower pressure spool (422; 558; 722) and engaging the first set of fan blades (426; 552; 726) such that rotation of the lower pressure spool (422; 558; 722) rotates the first set of fan blades (426; 552; 726) at a lower rotational speed than the rotational speed of the second set of fan blades (430; 554; 730); and characterized in that it further comprises: a second gear assembly (412; 584; 712) having an aperture (458; 756), wherein the lower pressure spool (422; 558; 722) passes through the aperture (458; 756) in said second gear assembly (412; 584; 712) to drive said first gear assembly (428; 560; 728); wherein the high pressure compressor comprises a first set of high pressure compressor blades and a subsequent set of high pressure compressor blades and wherein the second gear assembly (412; 584; 712) comprises an epicyclic gear having a sun gear (452; 588; 754), multiple planet gears (454; 592) and a ring gear (450; 586; 750), wherein the sun gear (452; 588; 754) of the second gear assembly (428; 584; 728) has said aperture (458; 756), and wherein the second gear assembly (428; 584; 728) is driven by the high pressure turbine (406; 604; 706) and is coupled to the first set of high pressure compressor blades (414; 578; 714), so that the first set of high pressure compressor blades (414; 578; 714) are driven to rotate at a lower rotational speed than the subsequent set of high pressure compressor blades (402; 580; 702). a high pressure spool (410; 582; 710); a high pressure compressor (402; 580; 702) mechanically coupled to the high pressure spool; a high pressure turbine (406; 604; 706) mechanically coupled to the high pressure spool (410; 582; 710); a lower pressure spool (422; 558; 722); and a lower pressure turbine (420; 608; 720) mechanically coupled to the lower pressure spool (422; 558; 722); a fan (424; 550; 724) having a first set of fan blades (426; 552; 726) and a second set of fan blades (430; 554; 730), the second set of fan blades (430; 554; 730) being located downstream of the first set of fan blades (426; 552; 726) and being operative to rotate at a rotational speed corresponding to a rotational speed of the lower pressure spool (422; 558; 722); a first gear assembly (428; 560; 728) mechanically coupled to the lower pressure spool (422; 558; 722) and engaging the first set of fan blades (426; 552; 726) such that rotation of the lower pressure spool (422; 558; 722) rotates the first set of fan blades (426; 552; 726) at a lower rotational speed than the rotational speed of the second set of fan blades (430; 554; 730); and characterized in that it further comprises: a second gear assembly (412; 584; 712) having an aperture (458; 756), wherein the lower pressure spool (422; 558; 722) passes through the aperture (458; 756) in said second gear assembly (412; 584; 712) to drive said first gear assembly (428; 560; 728);