The Royal Palace announcement in June last year via Twitter that the King would renounce the throne was re-tweeted more than 28,000 times, making it one of the most popular tweets of world leaders, according to the annual Twiplomacy report.
The study, released by public relations firm Burson-Marsteller on Tuesday, analyzed the Twitter use of accounts of 669 heads of state and government, foreign ministers and their institutions in 166 countries worldwide.
"Over the past years Twitter has become the channel of choice for digital diplomacy between world leaders, governments, foreign ministries and diplomats," the report states.
"Social media in general and Twitter in particular is no longer just an afterthought but an essential communication tool for governments to interact and broadcast 140 character messages and six-second soundbites."
It is a pleasure to open the Information Age exhibition today at the @ScienceMuseum and I hope people will enjoy visiting. Elizabeth R.— BritishMonarchy (@BritishMonarchy) October 24, 2014
Spanish Prime Minister Mariano Rajoy has also been a top-ranked world leader for Twitter use, rated 41 in this year’s report with more than 743,000 followers, just below Canadian Prime Minister Stephen Harper. Rajoy was also in the top 50 last year at number 42.
As of March 24th, the most-followed world leaders were US President Barack Obama at 57 million followers, Pope Francis at 20 million followers across his nine different language accounts and India’s Prime Minister Narendra Modi at about 11 million.
Turkish President Recep Tayyip Erdogan - who once vowed he would "wipe out Twitter", banning the social media site temporarily in the country - was also among the top five with 6.1 million followers.
The Pope beat Obama for most effective world leader, with an average of 9,929 re-tweets per tweet.
The report showed the Mexican presidency account to be the most prolific, with an average of 68 tweets per day.
"This study illustrates that governments are becoming savvier and more professional in the use of social media," said Jeremy Galbraith, CEO of Burson-Marsteller Europe, Middle East and Africa, in a statement.
"It is interesting to see how foreign ministries have honed their social strategies and built substantial dedicated teams to manage their online channels. We believe corporations can learn a lot from governments and their leaders on Twitter."