Kate Middleton, in Reiss, assumed her first royal duty this morning by joining her husband, Prince William, to welcome President Obama and First Lady Michelle Obama to the UK. The Duke and Duchess of Cambridge are home again following a 10-day honeymoon in the Seychelles, and they left with a special gift from the ruler of the remote island nation. The president and first lady, making the third official visit from a sitting head of state to Britain in 100 years, were first greeted by Queen Elizabeth and Prince Phillip, who is to celebrate his 90th birthday on June 10. William and Kate apparently discussed their upcoming California tour with the Obamas, then sat down to a lunch hosted by the queen. The president and first lady had to rearrange their travel plans and move their trip forward due to worries about how ash from the latest Iceland volcano will affect flying conditions. The Obamas are staying at Buckingham Palace for two nights, and this evening will dine at a royal banquet that William and Kate are not expected to attend.