ɪn jˈuːniən wɪððɪ ˌɑːɹtʃbˈɪʃəps mˈæks fɹˈænts ʌv kəlˈoʊn, klˈɛmɛnz wˈɛnzɪslˌaʊs ʌv tɹˈaɪɚ, ænd hˈaɪɚɹənˌɪməs dʒˈoʊsəf ʌv sˈæltsbɜːɡ hiː kənvˈoʊkt ðə kˈɑːŋɡɹəs ʌv ˈɛmz æt wˌɪtʃ twˈɛntiθɹˈiː ˌæntɪpˈeɪpəl ˈɑːɹɾɪkəlz, nˈoʊn æz ðɪ ʌv ˈɛmz, wɜː dɹˈɔːn ˌʌp ænd sˈaɪnd baɪ ðə plˌɛnɪpətˈɛnʃjɚɹiz ʌvðə fˈoːɹ ˌɑːɹtʃbˈɪʃəps ˌɔn twˈɛnti fˈaɪv ˈɔːɡəst wˈʌn θˈaʊzənd sˈɛvənhˈʌndɹɪd ˈeɪɾi sˈɪks.
In union with the Archbishops Max Franz of Cologne, Clemens Wenzeslaus of Trier, and Hieronymus Joseph of Salzburg he convoked the Congress of Ems at which twenty-three antipapal articles, known as the  of Ems, were drawn up and signed by the plenipotentiaries of the four archbishops on 25 August 1786.