Washington National Cathedral — the seat of the Episcopal Church, one of the world’s largest cathedrals and the host of the official prayer service for the presidential inauguration later this month — has decided to start hosting same-sex weddings.

In some ways, the announcement that is expected Wednesday morning is unsurprising for a denomination and a diocese that long ago took up the cause of marriage equality. But the cathedral’s stature and the image of same-sex couples exchanging vows in the soaring Gothic structure visited by a half-million tourists each year is symbolically powerful.