 In May 1996 , the National Gallery took on loan Velázquez 's Innocent X portrait and hung it alongside four Bacon paintings ; Head VI , Pope I ( 1951 ) , Pope 1961 and Pope 1965 . Peppiatt believes that Bacon would have disapproved of such a showing with a work he considered one of the finest ever painted , but writes that two , including Head VI , " stood up to it , and even enhanced its authority as one of the most penetrating studies of human nature and human power " . 
 In May 1996 , the National Gallery took on loan Velázquez <a href='null_genetive' title='1'><mark>'s</mark></a>Innocent X portrait and hung it alongside four Bacon paintings ; Head VI , Pope I ( 1951 ) , Pope 1961 and Pope 1965 . Peppiatt <a href='uninflect' title='2'><mark>believes</mark></a> that Bacon would <a href='been_done' title='3'><mark>have</mark></a> disapproved of such a showing with a work he considered one of the finest ever painted , but <a href='uninflect' title='4'><mark>writes</mark></a> that two , including Head VI , " stood up to it , and even enhanced its authority as one of the most penetrating studies of human nature and human power " . 
In May 1996 , the National Gallery took on loan Velázquez  Innocent X portrait and hung it alongside 4 Bacon paintings ; Head VI , Pope I ( 1951 ) , Pope 1961 and Pope 1965 . Peppiatt believe that Bacon would done disapproved of such a showin with a work he considered one of the finest eva painted , but write that 2 , including Head VI , " stood up to it , and even enhanced its authority as one of the most penetrating studies of human nature and human power " .