Gas turbine engine having an annular core bleed

A gas turbine engine comprising:

• a core including a compressor, one or more turbines each having one or more turbine stages, and a combustor, the combustor being located between the compressor and the turbine, and
• a bleed from the core, the bleed defined by a core duct, the core duct surrounding the turbine and the combustor and extending between the turbine and the combustor, the bleed comprising at least one inlet, a bypass passage, and an outlet, wherein
• the at least one inlet is located downstream of at least a first one of the turbine stages and upstream of at least a second one of the turbine stages,
• the bypass passage is an annular cavity, the annular cavity extending circumferentially around the core,
• the bypass passage leads from the at least one inlet at a first end to the outlet at a second end,
• the outlet exits into the core duct downstream of the turbine and upstream of an exhaust aperture of the core, and
• the turbine is arranged in use to drive the compressor, and the bleed is arranged to be controllable in use to selectively bleed air from the core through the at least one inlet and to thereby control the power delivered by the turbine to the compressor.