The Archbishop of Canterbury was among the first of society's leading figures to welcome the arrival of the daughter of the Duke and Duchess of Cambridge. He immediately prayed God's blessings on the Princess.
Archbishop Justin Welby said: "It's wonderful news that The Duke and Duchess of Cambridge have a healthy new baby girl. Like many here and abroad, I'm delighted for the Royal couple on this special day. May God bless them and both of their children with love, health and joy."
The Prince of Wales, who had previously expressed a desire for a granddaughter, and the Duchess of Cornwall said they were "absolutely delighted" at the birth of the Princess.
David Cameron tweeted:
Nick Clegg said:
Ed Miliband hinted at some of his personal experience with new borns:
But there was also reaction from the "people" on Twitter, some of it hilarious.
In an election joke that rapidly went viral, @will_full tweeted:
Jonathan Ross captured the mood of the moment with:
Peter Serafinowicz, the "male actress and comedienne", was on the other side of the political joke divide with:
On a more serious note, the Church of England published a prayer for the birth.
"Lord of all
We offer our deep thanksgiving for the gift of new life
And especially for the daughter born to the Duke and Duchess of Cambridge,
Sister to Prince George.
Pour your blessing upon the whole family, and be their light and guide in all that they are called to be and do in life.
Enfold them in your love and hope, now and always we pray
Through Jesus Christ our risen Lord. Amen"
The Bishop of Durham Paul Butler said: "Anybody who has been a parent or grandparent will know something of the joy and anxiety that the birth of a new baby brings. On behalf of the congregations of the Diocese of Durham I send our warmest congratulations to the Duke and Duchess on the birth of their daughter."
He added: "The Royal couple have already shown that they are modern parents able to juggle the pressures of a busy working life with those of being attentive parents - and I know that they will be a beacon of all that is good about family life with their new arrival. I hope that many in the North East will be praying for them in these early days.
"Christians hold to the belief that we are all royal children, Sons and Daughters of the King of Heaven. My prayer will be that this child may grow up knowing that she is loved not only by her family but also by the God who created her."
UKIP's Nigel Farage, meanwhile, said in an interview that he was happy the princess's weight was announced using the imperial system of measurement.
"Imperial measurements, proper measurements - eight pounds three ounces. Not some horrid kilogramme measurement. I'm very, very pleased. Perhaps that tells us where the Royal family really stand." He urged all UKIP candidates to take an hour out of campaigning to drink a toast to the princess. "I shall certainly be setting an example in that regard. After all, some things are worth interrupting politics for."
