Passage: There are many statues of George IV, a large number of which were erected during his reign. In the United Kingdom, they include a bronze statue of him on horseback by Sir Francis Chantrey in Trafalgar Square.In Edinburgh, "George IV Bridge" is a main street linking the Old Town High Street to the north over the ravine of the Cowgate, designed by the architect Thomas Hamilton in 1829 and completed in 1835. King's Cross, now a major transport hub sitting on the border of Camden and Islington in north London, takes its name from a short-lived monument erected to George IV in the early 1830s. A square and a neighbouring park in St Luke's, Islington, are also named after George IV.

Question: When were many of the statues of George IV originally built?
during his reign