Mr Collis took up the post in Riyadh in early 2015 after a long career across the Middle East. He was the ambassador to Syria from 2007 until 2012 and angered the Assad regime after he criticised the government’s crackdown on peaceful protesters.He left Damascus in February 2012 when the British government suspended diplomatic ties with Syria.Mr Collis also served as ambassador to Iraq from 2012 until 2014 and before was the UK enjoy to Doha. He is a graduate of Christ’s College, Cambridge and has five children. أول سفير بريطاني للمملكة يؤدي فريضة الحج بعد اسلامه:سيمون كوليز مع زوجته السيدة هدي في مكة. الحمدلله pic.twitter.com/Gk3323d3ce— فوزية البكر (@fawziah1) September 12, 2016 Britain’s ambassador to Saudi Arabia has been inundated with congratulations from across the Islamic world after it emerged that he converted to Islam and carried out the first Hajj pilgrimage to Mecca ever performed by a senior UK diplomat. The conversion of Simon Collis, the UK envoy to Riyadh, became public after pictures posted on Twitter showed him and his wife Huda wearing the traditional white garments of Muslim pilgrims in front of the British consulate in Mecca. The 60-year-old diplomat, who speaks fluent Arabic, confirmed the news in response to messages on Twitter.“God bless you. In brief: I converted to Islam after 30 years of living in Muslim societies and before marrying Huda,” he wrote. @HMASimonCollis @fawziah1 Masha’AllahNow you are like a newborn with no sins. May Allah bless you & accept youRemember us in your prayers— Gihan (@Gihanovich) September 14, 2016 The pictures of him and his wife were first posted by Fawziah Al-Bakr, a Saudi women’s rights activist. “The first British ambassador in Saudi Arabia is performing the Hajj with his wife Mrs Huda after he converted to Islam. Thanks be to God,” she wrote.He is believed to be the first British ambassador to carry out the Hajj pilgrimage although other ambassadors are thought to have converted to Islam in the past. The news led to a wave of online congratulations from Saudi Arabia and across the Islamic world, with many Muslims saluting Mr Collis as “Haji Simon” using the title reserved for those who make the pilgrimage to Mecca.Mr Collis converted in 2011 shortly before marrying his wife, who is Syrian. While his conversion was known to some fellow diplomats it was not public knowledge in Riyadh.The Foreign Office declined to comment, saying Mr Collis’s religion was a personal matter. While Mr Collis acknowledged many of the congratulatory messages coming in on Twitter, he declined interviews about his faith. Mr and Mrs Collis were among 1.8 million Muslim pilgrims from across the world to make the Hajj this year, according to the Saudi government. Islamic scripture calls for all able-bodied Muslims to make the journey to Mecca at least once in their lives. Mecca, the Saudi city where the Prophet Mohammed is said to have received the first revelations of the Koran, is the holiest site for Muslims and believers pray towards it every day. British ambassador to Saudi Arabia embraces Islam.. MASHA ALLAH Congrats Sir @HMASimonCollis & Family !!! https://t.co/JEv4HPTqgZ— Muhammad Aamir Raza (@BeingHuman_Aami) September 15, 2016 Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.