Mankind and horses have had a long history together. Historians believe that the earliest domestication of the horse probably happened around 3500 B.C.E. in Central Asia (likely modern-day Ukraine and Kazakhstan). Within the next few hundred years, they spread through the rest of the Europe, Asia and Africa, and were then brought to the Americas in the 1500s by Spanish conquistadors. A few escaped horses found the vast plains of America to be irresistible, and large populations of wild horses (still around today in some places) quickly sprang up throughout the Great Plains.
It's easy to see why horses became so popular. Their size and strength allow us to accomplish a variety of tasks we couldn't do by ourselves, and their speed and stamina were instrumental in helping mankind travel around the world and conquer it. Besides these purely utilitarian reasons, horses are also incredibly intelligent and generally good-natured animals who take very well to training and make for great companions.
In this video, accomplished horse trainer David Lichmann brings some of his horses to the beach. He brings them to the edge of the water and then he starts to speak to them. They respond to his every command, mimicking him as he marches and performing other elaborate feats of training and coordination. Lichmann is a master horse whisperer, one of legendary horse trainer Pat Parelli's top students. He's spent countless hours working closely with thousands of horses, so it's not surprising that he has such control over the ones seen here.