The Royal Arms of the United Kingdom (as displayed outside Scotland) since the accession of Queen Victoria in 1837, featuring the arms of England in the first and third quarter, Scotland in the second, and Ireland in the fourth
The Hanoverian succession came about as a result of the Act of Settlement 1701, passed by the English Parliament. In return for access to the English plantations in North America, the Hanoverian succession and the Union were ratified by the Scottish Parliament in 1707.
The house name Windsor was adopted in 1917, during the First World War. It was changed from Saxe-Coburg-Gotha because of wartime anti-German sentiment. The heirs of Elizabeth II, by her royal proclamation, will remain part of the House of Windsor (barring any future proclamation to the contrary).
Following the Acts of Union, regnal numbering of subsequent monarchs followed on from those of England. William IV, Edward VII, Edward VIII and Elizabeth II all taking the next number in the English sequence. As a result of Scottish opposition to the use of the style Elizabeth II, it was announced that all future monarchs would take the next number from either the English or Scottish sequence, whichever was higher. This new rule was consistent, in that had it been applied since the Union, it would not have changed the regnal numbers of any previous post-union monarch. For example, should any King James come to the throne in the future, he would be styled James VIII.