After the execution of King Charles I in January, the English Parliament now officially abolishes the institution of the monarchy and the House of Lords, reducing the legislature from a bicameral to a unicameral system.
Editors. "Parliament abolishes the Monarchy". The Literary Encyclopedia. First published 01 March 2011
[http://www.litencyc.com/php/stopics.php?rec=true&UID=2374, accessed 31 January 2015.]