Irish President Michael Higgins waswelcomed in Londonon Tuesday by Prince Charles and his wife Camilla, as the firstofficial visit to Britain by an Irish head of state got under way, dpa reported.The four-day visit comes more than 90 years after Ireland effectivelybecame independent from Britain, and follows Queen Elizabeth II'shistoric first trip to Ireland in 2011.Relations have been transformed since the signing of the 1998 GoodFriday Agreement, which ended decades of conflict in the Britishprovince of Northern Ireland.