It is the Cross of St George of England with more than the centre of the cross the defend of the traditional arms of East Anglia, blue with three gold crowns. The arms are efficiently just like the compact arms of Sweden, from where by the East Anglian royal dynasty, https://medieval-flag76316.canariblogs.com/the-single-best-strategy-to-use-for-medieval-banners-and-flags-48025088