It was Erik XIV who, at his coronation in 1560, changed the open crown of the Middle Ages for the modern closed kind carried to this day. The two crowned Lion Supporters of the Great Coat of Arms also date back to the latter part of the sixteenth century and were introduced by Eric's half-brother and successor King John III.
In the Act of 15th May 1908 it is specifically stated that these Lions have forked tails (klufna svansar) to emphasise their Renaissance origin under John III as distinct from the medieval Folkung Lions in the second and third Quarters of the Shield. They are looking over their shoulders as they are not only supporting the Shield, they are guarding it.