In Eagle v. Oldham, 116 Ark. 565, 174 S.W. 1176 (1915), for the proposition that erroneous property descriptions in a will can be cured through extrinsic evidence of the testator's intent. The paramount principle in the interpretation of wills is that the intention of the testator will govern. In Re Estate of Conover, 304 Ark. 268, 801 S.W.2d 299 (1990). The intent of the testator is to be gathered from the four corners of the instrument, itself, considering the language used and giving meaning to all of its provisions, when possible to do so. Id. Only when there is uncertainty as to the testator's intentions from looking at the language of the will, may the court read the language employed by the testator in the light of circumstances existing when the will was written. Id. However, the probate court is not required to resort to forced construction and extend the meaning of the language in the will by speculating about surrounding circumstances. See Acklin v. Riddell, 42 Ark. App. 230, 856 S.W.2d 322 (1993). Moreover, it is presumed that the testator knew the contents of the will that he executed. Chlanda v. Estate of Fuller, 326 Ark. 551, 932 S.W.2d 760 (1996). Probate matters are reviewed de novo on appeal, but we will not reverse the probate judge's findings unless they are clearly erroneous. Mangum v. Estate of Fuller, 303 Ark. 411, 797 S.W.2d 452 (1990). Clifton Bond testified that he drafted the decedent's last will and testament according to the decedent's instructions. According to Bond, the decedent had access to tax assessor's records, and understood the will's terms. In fact, according to Bond, the decedent discovered a discrepancy in the devise of two parcels of real estate, and subsequently had those mistakes corrected by codicil. However, appellees' reliance on Eagle is misplaced because the facts found in that case are easily distinguished from those found in the case before the court. In the present case, the legal descriptions are correct, and the challenge appellee had was to the devise made by the terms of the will. We believe that the language employed by the testator is unambiguous. the mere fact that some of the beneficiaries did not receive the property that they thought they would receive does not render the language employed ambiguous. Moreover, it was improper to permit the introduction of extrinsic evidence to create an ambiguity, as was done in the present case. Here, although appellees contend that the language of the codicil creates an ambiguity, a plain reading of the will and second codicil clearly shows that the testator merely executed the codicil to dispose of all property not disposed of under the terms of the will. Because we hold that the probate judge erred in finding that an ambiguity existed in the terms of the will and codicil, we need not address appellant's remaining argument. Reversed and remanded.