A rotary seal comprising: a first annular element formed from a metallic material and having a first axially extending flange and a first radially extending flange extending radially from a proximal end of the first axially extending flange; a second annular element formed from a metallic material and having a second axially extending flange and a second radially extending flange extending radially from a proximal end of the second axially extending flange in the same direction as the first radially extending flange; wherein the second annular element is fixed to the first annular element, the second axially-extending flange being received radially on the first axially-extending flange and the second radially extending flange being spaced axially from the first radially extending flange to define a pocket therebetween; a seal element located in the pocket axially between the first radially extending flange and the second radially extending flange and making a first sealing engagement against a first surface of the first radially extending flange and making a second sealing engagement against a second surface of the second radially extending flange axially opposed to the first surface of the first radially extending flange; characterised in that a reaction engagement is formed between the seal element and one of the first and second radially extending flanges (28, 34), and the reaction engagement is generally opposite the first or second sealing engagement (48, 54) of the seal element with the other of the first and second radially extending flanges (28, 34), and the reaction engagement comprises a third raised lip formed on one of the first or the second radially extending flanges (28, 34). a first annular element formed from a metallic material and having a first axially extending flange and a first radially extending flange extending radially from a proximal end of the first axially extending flange; a second annular element formed from a metallic material and having a second axially extending flange and a second radially extending flange extending radially from a proximal end of the second axially extending flange in the same direction as the first radially extending flange; wherein the second annular element is fixed to the first annular element, the second axially-extending flange being received radially on the first axially-extending flange and the second radially extending flange being spaced axially from the first radially extending flange to define a pocket therebetween; a seal element located in the pocket axially between the first radially extending flange and the second radially extending flange and making a first sealing engagement against a first surface of the first radially extending flange and making a second sealing engagement against a second surface of the second radially extending flange axially opposed to the first surface of the first radially extending flange; characterised in that a reaction engagement is formed between the seal element and one of the first and second radially extending flanges (28, 34), and the reaction engagement is generally opposite the first or second sealing engagement (48, 54) of the seal element with the other of the first and second radially extending flanges (28, 34), and the reaction engagement comprises a third raised lip formed on one of the first or the second radially extending flanges (28, 34).