The Duke of York has become the first member of the Royal Family to join Twitter.
Prince Andrew chose @TheDukeOfYork as his handle for the micro-blogging site.
But his arrival prompted mixed reactions from other tweeters, as some pointed to his friendship with sex offender Jeffrey Epstein and others pretended to confuse him with a pub.
The prince served for 22 years in the Royal Navy as a helicopter pilot, and until 2011 was the UK's trade envoy.
His first tweet was "Welcome to my Twitter account - AY". If the tweets are signed AY, they will have been written by Prince Andrew himself.
The sign-off led one user to ask if his account had been hacked by Ali G, Sacha Baron Cohen's comedy character, who used a similar sounding catchphrase.
Another tweeted: "Yo how's Jeffrey Epstein?", a reference to the American billionaire and friend of the duke who was convicted of soliciting a minor for prostitution.
But there were well-wishers and some friendly advice among those welcoming the royal to Twitter, a site where users communicate with their followers using 140 characters or less.
Television presenter Eamonn Holmes suggested "in a caring way" that Prince Andrew's account needed "a more personal touch to be effective".
BBC royal correspondent Peter Hunt said after the Royal Family first went on Facebook, an extra layer of security had to be used to block some of the abuse some people wanted to post.
The duke's decision to start tweeting coincided with the launch of the Duke of York Award for Technical Education as he visited the Black Country University Technical College - a new school offering year 10 and year 12 students the opportunity to focus on science and engineering subjects in a specialist environment.
A spokesman for Prince Andrew said he had long been someone who embraced new technology.
"He was in fact the first member of the British Royal Family to tweet on the British Monarchy (account) when he visited Tech City. The logical next step was to tweet individually."
Asked about the derogatory tweets, the spokesman added: "The duke is a champion of free speech. For him it's about telling people what he's doing."
Within two hours of going online, the duke's account had amassed more than 3,000 followers.