Politicians, religious leaders and public figures have issued Rosh Hashanah greetings to the Jewish community.
In a video message from Downing Street, Prime Minister David Cameron said the beginning of the Jewish year 5774 was a time for “millions around the world to reflect on the past 12 months”.
Mr Cameron said: “At this important time for the Jewish faith let us join you in praying for a New Year that will achieve progress towards a lasting peace for Israel and the Middle East.
“I would also like to take this opportunity to once again applaud Britain’s strong Jewish community for your historic and immense contribution to our country, where you have given and achieved so much to the benefit of us all. I wish you all Shana Tova.”
Chief Rabbi Ephraim Mirvis said: “Valerie and I extend to you all our very best wishes for a happy, healthy, peaceful and fulfilling New Year.
"I look forward to working together with you to develop and grow our local congregations and our wonderful British and Commonwealth Jewish communities for the benefit of us all and all of Am Yisrael.”
In his annual Rosh Hashanah message, Israeli Prime Minister Benjamin Netanyahu said “Jewish unity” was a “major part of our collective strength”.
He reflected on the civil war in Syria and Israel’s current peace talks with the Palestinians.
“Together we can continue to achieve great things for Jewish people and the world," said Mr Netanyahu.
Israeli President Shimon Peres said: “We are going through a stormy time but there is no room to lose hope and to lose faith.
"I do believe that out of this very complicated situation we can carry the hope of a better year for all mankind, for the Jewish people, for all your families, for each of us. Let’s pray for a happy New Year for all of us and to each of us.”
Britain’s Deputy Prime Minister Nick Clegg also praised Anglo-Jewry’s contribution.
The Liberal Democrat leader said: “The central principles of your faith are woven into the fabric of what makes us stronger as a society. That commitment to kindness, peace and justice, as well as progress through education and hard work."
Labour leader Ed Miliband said that “these ten days… are an important time for personal reflection”.
He expressed his gratitude to the Jewish community and his “admiration for its values” which include “a reaffirmation of life, the pursuit of justice and a commitment to make the world a better place".
The hopes for peace in the Middle East were echoed by Foreign Secretary William Hague, who said: “In these often tumultuous and difficult times for the Middle East, I share your heartfelt hope that that the new year will bring Israel and the whole region closer to peace.
“I am delighted to wish you and your families a very happy new year. L’Shanah Tovah U’Metuka.”
Archbishop of Canterbury Justin Welby said he shared the Jewish community’s desire for “new beginnings in this season of remembrance and renewal”.
Reflecting on his first months in the role he said it had been moving to visit Jerusalem, the Kotel and Yad Vashem. Rev Welby said he was “grateful” for the work of the Council of Christians and Jews.
“One of the highlights of the Rosh Hashanah service for me is the thanksgiving song of Hannah, which speaks of God’s power to change, to give all that is needed and more,” said the Archbishop.
A Shana Tova message also came from Iran's new President Hassan Rouhani, who tweeted: "I wish all Jews, especially Iranian Jews, a blessed Rosh Hashanah."
The message drew a swift response from Israeli Prime Minister Benjamin Netanyahu. He said: "I am not impressed by greetings coming from the regime which just last week threatened to destroy Israel.
"The Iranian regime will be judged solely on its deeds, not its greetings."