OLM JUBILEE - View Photos of the celebration. The Oldest English Speaking Catholic Parish in Brussels, Our Lady of Mercy, celebrated their 50th Anniversary with a Jubilee Mass on December 5th and a pilgrimage to Leuven on December 6th. ACAA alumni extend their congratulations and prayers during this time of celebration. Many ACAA alumni were gifted with pastoral assignments at OLM over the years enabling wonderful opportunities for experiencing the gift of parish life. ACAA President, Reverend Robert Flannery, was the homilist at the Jubilee Mass.