A gas turbine comprising: a first annular gas flow path; a second annular gas flow path located radially outwardly from the first gas flow path; in series order, a multi-stage fan, radially inboard portions of a first set of high pressure compressor blades, a second set of high pressure compressor blades, a combustion section and a high pressure turbine, positioned along the first gas flow path; and in series order, the multi-stage fan and radially outboard portions of the first set of high pressure compressor blades, positioned along the second gas flow path such that the inboard portions of the first set of high pressure compressor blades, the second set of high pressure compressor blades, the combustion section and the high pressure turbine are not positioned along the second gas flow path; a first spool and a second spool; the high pressure turbine being operative to drive the first set of high pressure compressor blades and the subsequent sets of high pressure compressor blades via the first spool; the multi-stage fan being operative to be driven by the second spool; the gas turbine further comprising: a lower pressure turbine positioned along the first gas flow path, the lower pressure turbine being operative to drive the multi-stage fan via the second spool, the lower pressure turbine being an intermediate pressure turbine; the gas turbine further comprises a low pressure turbine positioned along the first gas flow path downstream of the intermediate pressure turbine, the low pressure turbine being operative to drive a third spool; an auxiliary fan located upstream of the multi-stage fan, the auxiliary fan being operative to be driven by the low pressure turbine via the third spool; and a third gas flow path located radially outwardly of the second gas flow path; characterised in that: the auxiliary fan is operative to direct a flow of gas along the third gas flow path without directing a flow of gas along the first gas flow path or along the second gas flow path. a first annular gas flow path; a second annular gas flow path located radially outwardly from the first gas flow path; in series order, a multi-stage fan, radially inboard portions of a first set of high pressure compressor blades, a second set of high pressure compressor blades, a combustion section and a high pressure turbine, positioned along the first gas flow path; and in series order, the multi-stage fan and radially outboard portions of the first set of high pressure compressor blades, positioned along the second gas flow path such that the inboard portions of the first set of high pressure compressor blades, the second set of high pressure compressor blades, the combustion section and the high pressure turbine are not positioned along the second gas flow path; a first spool and a second spool; the high pressure turbine being operative to drive the first set of high pressure compressor blades and the subsequent sets of high pressure compressor blades via the first spool; the multi-stage fan being operative to be driven by the second spool; the gas turbine further comprising: a lower pressure turbine positioned along the first gas flow path, the lower pressure turbine being operative to drive the multi-stage fan via the second spool, the lower pressure turbine being an intermediate pressure turbine; the gas turbine further comprises a low pressure turbine positioned along the first gas flow path downstream of the intermediate pressure turbine, the low pressure turbine being operative to drive a third spool; an auxiliary fan located upstream of the multi-stage fan, the auxiliary fan being operative to be driven by the low pressure turbine via the third spool; and a third gas flow path located radially outwardly of the second gas flow path; characterised in that: the auxiliary fan is operative to direct a flow of gas along the third gas flow path without directing a flow of gas along the first gas flow path or along the second gas flow path. a lower pressure turbine positioned along the first gas flow path, the lower pressure turbine being operative to drive the multi-stage fan via the second spool, the lower pressure turbine being an intermediate pressure turbine; the gas turbine further comprises a low pressure turbine positioned along the first gas flow path downstream of the intermediate pressure turbine, the low pressure turbine being operative to drive a third spool; an auxiliary fan located upstream of the multi-stage fan, the auxiliary fan being operative to be driven by the low pressure turbine via the third spool; and a third gas flow path located radially outwardly of the second gas flow path; characterised in that: the auxiliary fan is operative to direct a flow of gas along the third gas flow path without directing a flow of gas along the first gas flow path or along the second gas flow path. the auxiliary fan is operative to direct a flow of gas along the third gas flow path without directing a flow of gas along the first gas flow path or along the second gas flow path.