A gas turbine engine comprising: axially adjacent first and second components each having a main gas path facing surface within an engine casing, wherein the first component is a seal segment located around the rotating turbine blades and the second component is a nozzle guide vane, an inter component cavity located between said first and second components on the outboard side of the main gas path, characterised in that it comprises: an axial restrictor in the form of a retaining ring located within the inter component cavity to axially restrict movement of the first or second component relative to either or both of the other of the first and second component or the engine casing, wherein the retaining ring is radially located in the engine casing or other of the first and second component and includes a radially inner surface; and, a retaining element, comprising: a main body having a circumferential length extending around the gas turbine engine and an axial length which extends between said axially adjacent first and second components when in use; and, an obstructing portion located between the radially inner surface of the retaining ring and an opposing second radial surface of the other of the first or second component or engine casing, so as to restrict the radial movement of the retaining ring, in use; the retaining ring has a radial component which is received within a corresponding slot in the engine casing to provide an axial facing surface which abuts the first or second component to provide a shear axial restraint for the first or second component. axially adjacent first and second components each having a main gas path facing surface within an engine casing, wherein the first component is a seal segment located around the rotating turbine blades and the second component is a nozzle guide vane, an inter component cavity located between said first and second components on the outboard side of the main gas path, characterised in that it comprises: an axial restrictor in the form of a retaining ring located within the inter component cavity to axially restrict movement of the first or second component relative to either or both of the other of the first and second component or the engine casing, wherein the retaining ring is radially located in the engine casing or other of the first and second component and includes a radially inner surface; and, a retaining element, comprising: a main body having a circumferential length extending around the gas turbine engine and an axial length which extends between said axially adjacent first and second components when in use; and, an obstructing portion located between the radially inner surface of the retaining ring and an opposing second radial surface of the other of the first or second component or engine casing, so as to restrict the radial movement of the retaining ring, in use; the retaining ring has a radial component which is received within a corresponding slot in the engine casing to provide an axial facing surface which abuts the first or second component to provide a shear axial restraint for the first or second component. an axial restrictor in the form of a retaining ring located within the inter component cavity to axially restrict movement of the first or second component relative to either or both of the other of the first and second component or the engine casing, wherein the retaining ring is radially located in the engine casing or other of the first and second component and includes a radially inner surface; and, a retaining element, comprising: a main body having a circumferential length extending around the gas turbine engine and an axial length which extends between said axially adjacent first and second components when in use; and, an obstructing portion located between the radially inner surface of the retaining ring and an opposing second radial surface of the other of the first or second component or engine casing, so as to restrict the radial movement of the retaining ring, in use; a main body having a circumferential length extending around the gas turbine engine and an axial length which extends between said axially adjacent first and second components when in use; and, an obstructing portion located between the radially inner surface of the retaining ring and an opposing second radial surface of the other of the first or second component or engine casing, so as to restrict the radial movement of the retaining ring, in use; the retaining ring has a radial component which is received within a corresponding slot in the engine casing to provide an axial facing surface which abuts the first or second component to provide a shear axial restraint for the first or second component.