1. In 1873 the respondents purchased the share of which the appellant claims pre-emption. The appellant denied the title of the vendor, but the respondents instituted a suit against the appellant, and having succeeded in establishing their vendor's title, they obtained a decree for possession. The appellant then instituted the present suit to have the sale to the respondents set aside, and a sale concluded in his favour as pre-emptor. It is contended that the respondents having succeeded in obtaining a decree for possession in a suit to which the appellant was a party, he is now debarred from suing to enforce a claim which he might have asserted in reply to the claim formerly made by the respondents, and decreed in their favour. We admit the validity of the plea. It would have been a good answer to the claim then advanced that the sale on which it was founded was invalid, in that the defendant was entitled to a prior right of purchase and ready to exercise it. In Srimut Rajah Mootoo Vijaya v. Katama Natchiar 11 Moore's Ind. App., at p. 73, it was declared by the Privy Council that, 'when a plaintiff claims an estate, and the defendant, being in possession, resists that claim, he is bound to resist it upon all the grounds that it is possible to him, according to his knowledge, then to bring forward,' and that, if he fails to do so, he is estopped from asserting any of them thereafter. This dictum was cited and re-affirmed in Woomatara, Debia v. Unnopoorna Dassee 11 B.L.R.P.C., at p. 169, decided by the Privy Council on May 13th, 1873. We must, then, allow the plea urged by the respondents and dismiss this appeal with costs. See Maktum Valad Mohidin v. Imam Valad Mohidin 10 Bom. H.C.R., 293 and Janaki Ammal v. Kamalathammal 7 Mad. H.C.P., 263.