A powerful earthquake destroys large portions of the <a href="https://en.wikipedia.org/wiki/Walls_of_Constantinople" id="mwEQ" rel="mw:WikiLink" title="Walls of Constantinople">Walls of Constantinople</a>, including 57 towers.<sup about="#mwt15" class="mw-ref reference" data-mw='{"name":"ref","attrs":{},"body":{"id":"mw-reference-text-cite_note-1"}}' id="cite_ref-1" rel="dc:references" typeof="mw:Extension/ref"><a href="./November_6#cite_note-1" id="mwEg" style="counter-reset: mw-Ref 1;"><span class="mw-reflink-text" id="mwEw">[1]</span></a></sup>
<span class="mw-reference-text" id="mw-reference-text-cite_note-1"><cite about="#mwt12" class="citation cs2" id="CITEREFPhilippidesHanak2011">Philippides, Marios; Hanak, Walter K. (2011), <a class="external text" href="https://books.google.com/books?id=qvvdVXckfqQ" id="mwBMg" rel="mw:ExtLink nofollow"><i id="mwBMk">The Siege and the Fall of Constantinople in 1453: Historiography, Topography and Military Studies</i></a>, Ashgate Publishing, Ltd., p.<span id="mwBMo" typeof="mw:Entity"> </span>299, <a class="mw-redirect" href="./ISBN_(identifier)" id="mwBMs" rel="mw:WikiLink" title="ISBN (identifier)">ISBN</a><span id="mwBMw" typeof="mw:Entity"> </span><a href="./Special:BookSources/978-1-4094-1064-5" id="mwBM0" rel="mw:WikiLink" title="Special:BookSources/978-1-4094-1064-5"><bdi id="mwBM4">978-1-4094-1064-5</bdi></a></cite><span about="#mwt12" class="Z3988" id="mwBM8" title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&amp;rft.genre=book&amp;rft.btitle=The+Siege+and+the+Fall+of+Constantinople+in+1453%3A+Historiography%2C+Topography+and+Military+Studies&amp;rft.pages=299&amp;rft.pub=Ashgate+Publishing%2C+Ltd.&amp;rft.date=2011&amp;rft.isbn=978-1-4094-1064-5&amp;rft.aulast=Philippides&amp;rft.aufirst=Marios&amp;rft.au=Hanak%2C+Walter+K.&amp;rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DqvvdVXckfqQ&amp;rfr_id=info%3Asid%2Fen.wikipedia.org%3ANovember+6"></span></span>