The arts of the sword as we know them today probably began with Iizasa Choisai the founder of the Tenshin Shoden Katori Shinto Ryu. Also during the 15th century Hayashizaki Jinsuke Minamoto no Shigenobu collected techniques from different warrior schools into a form he called Iai Jutsu or Iaido. The difference was that the new forms were all defensive. You responded to an (surprise) attack by drawing your sword and cutting down your enemies. The term Iai Jutsu does not, translate into "The art of drawing the sword", but rather "Instant Awareness". You should be able to respond to any threat instantaneously and in such a way be able to avoid being attacked. Nowadays Iaido represents the intrinsic form of Japanese Budo and is used as a form of mental and physical discipline, emphasising correct technique and form and character development. 

Therefore Iaido is the art of reacting to a surprise attack by counter attacking with a sword.

An in-depth reading of the Japanese characters for iaido is:

I = being, AI = harmony, DO = way . "The way of harmonising oneself in action”.

The Iaidoka (a practitioner of iaido) wields a sword: not to control the opponent, but to control himself. Iaido is mainly performed solo as a series of forms/kata. The Iaidoka executes various techniques against single or multiple imaginary opponents. Each of these forms begins and ends with the sword sheathed.  There are forms/kata with two persons also practiced, which demonstrate attack, defence and counter techniques using long sword (bokken or iaito), short sword (wakizashi) and knife (tanto) and also unarmed against an armed attacker. In addition to sword technique, practitioners require focus and concentration in order to maintain the feeling of a real fight. In order to properly perform each technique/ waza, Iaidoka also learn posture and movement, grip, and swing.

Iaidoka practice to prepare for a surprise attack, where an immediate, efficient solution to the problem of aggression is necessary. Therefore, the technique is highly refined. Every unnecessary movement is cut away. Technique is simple and direct. The training method is aimed towards development of the practitioner’s every mental and physical resources.

Iaido is an authentic martial art that proved its martial values in a time of constant battle and warfare, that was preserved and passed on directly from teacher to student over generations in an unbroken lineage for 450 years. Iaidoka developed the mind towards an ultimately peaceful, harmonious, and active state ready to react and deal with any life situation. Ki Ken Tai Ichi - Spirit, Sword and Body as One.

Iaido can be segmented into four main parts as follows.

1. Nukitsuke - This is the first strike, though single handed, it should be effective and performed with focus and purpose. It should make kirioroshi unnecessary.

2. Kiritsuke / Kirioroshi - Main two handed cut, the definitive cut, carried out with power and control.

3. Chiburi - Blood shake off. Maximum zanshin as the confrontation may not be over.

4. Noto - Re-sheathing of the blade. again maximum zanshin.

Alongside the physical aspects of the forms there are the mental aspects of swordsmanship. To become one with the sword and achieve a state of "No-Mind", it is necessary to have an understanding of Metsuke (correct use of the eyes), Maai (combative distance) and Ma (timing). 

The Five Kamaes ( Attitudes ):

 Gedan no kamae - low level attitude (Earth). A kamae of waiting or inviting, a negative kamae.

 Chudan no kamae - Middle level attitude (Water). Be observant, calm and waiting but fully aware, a positive kamae.

 Jodan no kamae - High level attitude (Heaven). A strong aggressive kamae of total attack, think not of defense, a positive kamae.

 Hasso no kamae - Waiting or inviting attitude ( In ) Sword raised point straight up with 45 degree angle backwards, Tsuba in line with mouth, cutting edge facing opponent. a semi positive kamae.

 Waki no kamae - Hidden attitude ( Yo ), the sword is concealed behind your back, right foot back, body half turned. Your strength as well as your weapon is hidden, a variety of options are open from this attitude. A positive kamae.

Finally a kamae not usually listed with the five main ones is Kamae-Otoku, this is the attitude of mutual withdrawal. the point of the sword faces the opponents knee with the wrists exposed.

Iaido is normally practiced wearing a hakama (pleated Japanese trousers) and keiko gi (training jacket). An iai obi (sword belt) is worn under the hakama cords to hold the sword in place.