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 , and the reaction engagement is generally opposite the first or second sealing engagement of the seal element with the other of the first and second radially extending flanges , and the reaction engagement comprises a third raised lip formed on one of the first or the second radially extending flanges . 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 , and the reaction engagement is generally opposite the first or second sealing engagement of the seal element with the other of the first and second radially extending flanges , and the reaction engagement comprises a third raised lip formed on one of the first or the second radially extending flanges . <EOS>