Originally cultivated in the Ottoman Empire (present-day Turkey), tulips were imported into Holland in the sixteenth century. When Carolus Clusius wrote the first major book on tulips in 1592, they became so popular that his garden was raided and bulbs stolen on a regular basis. As the Dutch Golden Age grew, so did this curvaceous and colorful flower. They became popular in paintings and festivals. In the mid-seventeenth century, tulips were so popular that they created the first economic bubble, known as "Tulip Mania" (tulipomania). As people bought up bulbs they became so expensive that they were used as money until the market in them crashed.