2 added 7 characters in body
source | link

Here is how it mattered that he was a lefty. 
Many Near Eastern archeological remains show that the entrances to castles were constructed in a particular fashion which prevented sword-use by the right-handed majority. The entrances were narrow tunnels where the visitor had to keep his left side (where a right-hander’s sword would hang) against the left side of the tunnel, leaving his right arm free to present the castle guard with tribute and/or documents of any kind. There was a place for the castle guard on the entrance’s right side, at the point where it opened into the actual castle: so the guard could see that the right hand was safely empty, while other guards lined the left side of the tunnel to feel the visitor’s left leg & check for a sword. 

It was a security system: with a hole that a lefty could exploit!

Here is how it mattered that he was a lefty. Many Near Eastern archeological remains show that the entrances to castles were constructed in a particular fashion which prevented sword-use by the right-handed majority. The entrances were narrow tunnels where the visitor had to keep his left side (where a right-hander’s sword would hang) against the left side of the tunnel, leaving his right arm free to present the castle guard with tribute and/or documents of any kind. There was a place for the castle guard on the entrance’s right side, at the point where it opened into the actual castle: so the guard could see that the right hand was safely empty, while other guards lined the left side of the tunnel to feel the visitor’s left leg & check for a sword. It was a security system: with a hole that a lefty could exploit!

Here is how it mattered that he was a lefty. 
Many Near Eastern archeological remains show that the entrances to castles were constructed in a particular fashion which prevented sword-use by the right-handed majority. The entrances were narrow tunnels where the visitor had to keep his left side (where a right-hander’s sword would hang) against the left side of the tunnel, leaving his right arm free to present the castle guard with tribute and/or documents of any kind. There was a place for the castle guard on the entrance’s right side, at the point where it opened into the actual castle: so the guard could see that the right hand was safely empty, while other guards lined the left side of the tunnel to feel the visitor’s left leg & check for a sword. 

It was a security system: with a hole that a lefty could exploit!

1
source | link

Here is how it mattered that he was a lefty. Many Near Eastern archeological remains show that the entrances to castles were constructed in a particular fashion which prevented sword-use by the right-handed majority. The entrances were narrow tunnels where the visitor had to keep his left side (where a right-hander’s sword would hang) against the left side of the tunnel, leaving his right arm free to present the castle guard with tribute and/or documents of any kind. There was a place for the castle guard on the entrance’s right side, at the point where it opened into the actual castle: so the guard could see that the right hand was safely empty, while other guards lined the left side of the tunnel to feel the visitor’s left leg & check for a sword. It was a security system: with a hole that a lefty could exploit!