Three Roman <a href="https://en.wikipedia.org/wiki/Papal_legate" id="mwHw" rel="mw:WikiLink" title="Papal legate">legates</a> break relations between <a href="https://en.wikipedia.org/wiki/Western_Christianity" id="mwIA" rel="mw:WikiLink" title="Western Christianity">Western</a> and <a href="https://en.wikipedia.org/wiki/Eastern_Christianity" id="mwIQ" rel="mw:WikiLink" title="Eastern Christianity">Eastern Christian Churches</a> through the act of placing a <a href="https://en.wikipedia.org/wiki/Papal_bull" id="mwIg" rel="mw:WikiLink" title="Papal bull">Papal bull</a> (of doubtful validity) of <a href="https://en.wikipedia.org/wiki/Excommunication" id="mwIw" rel="mw:WikiLink" title="Excommunication">Excommunication</a> on the altar of <a href="https://en.wikipedia.org/wiki/Hagia_Sophia" id="mwJA" rel="mw:WikiLink" title="Hagia Sophia">Hagia Sophia</a> during Saturday afternoon divine liturgy. Historians frequently describe the event as the formal start of the <a href="https://en.wikipedia.org/wiki/East–West_Schism" id="mwJQ" rel="mw:WikiLink" title="East–West Schism">East–West Schism</a>.