The 20th century saw attempts to restore lines of King Charles Spaniels to the breed of Charles II's time. These included the unsuccessful Toy Trawler Spaniel and the now popular Cavalier King Charles Spaniel. The Cavalier is slightly larger, with a flat head and a longer nose, while the King Charles is smaller, with a domed head and a flat face. Historically the breeds that were merged into the King Charles Spaniel were used for hunting; due to their stature they were not well suited. They have kept their hunting instincts, but do not exhibit high energy and are better suited to being lapdogs. The modern breed is prone to several health problems, including cardiac conditions and a range of eye problems.