Iaido began after the warring period in Japan was over. Once the wars were over the battles that resulted were typically inside cities and not large fields. During this time the samurai moved from spears, and tachi (a longer typically more curved blade used from horse back) to a slightly shorter less curved blade an uchigatana otherwise known as the common katana we see today.
Iaido originated as a means of warriors to keep their skills up, continue to practice, and a means of self-defense for the grounds of fighting in a city capital or building. In recent years, Iaido has become a form similar to meditation. Iaido and Aikido are two separate arts but they both complement each other immensely.
In Iaido you practice with Bokken (wooden sword), Iaito (mock aluminum training blade to better mimic the real thing), or a Shinken (live blade with a sharp edge used only at very high levels with care). In Iaido, you learn to cultivate a strong sense of alertness, and a strong mental focus, you also learn how to use the power of your sphere and transmit it into a very fine angle.
At Aikido of Central New York, part of our weapons training includes the opportunity to practice Iaido.