On Australia Day Prime Minister Tony Abbott awarded knighthoods to two people. But if you were watching social media, you could be forgiven for only having heard about Prince Philip.

Mr Abbott controversially knighted the Duke of Edinburgh, Prince Philip, in the order of Australia, as well as former defence force chief Angus Houston.

But in the social media storm that erupted in the three days following the announcement, Sir Angus was mentioned a mere 1696 times, to Prince Philip's 29,333.

The hashtag to have dominated the online discussion on the issue was #knightmare, the most popular hashtag by over 60 per cent.

Other hashtags used in the three-day period included #SirPrincePhilip (17 per cent), #knightsanddames (14 per cent) and #toxictony (8.5 per cent), which although not unique to the issue, experienced a resurgence in the three-day period.

Last week #knightmare was a hashtag sometimes used in conjunction with the University of Central Florida basketball team, the UCF Knights.

But as Australia Day dawned and news spread of the Prime Minister's decision to knight the Duke of Edinburgh, the hashtag found a new calling.

From 3am on Australia Day to 9am on Wednesday #Knightmare was mentioned online 4325 times, peaking three times over the period, according to figures from social media monitoring tool Radian6.

Independent social media strategist Tiphereth Gloria said, while #knightmare was not a unique hashtag, someone found it as a pun and "it just took off."

She said the three peaks, (713 mentions at 9pm on Monday, 798 at 3pm on Tuesday and 960 at 9am on Wednesday) are a good reflection of the ebb and flow of the news cycle.

"These things start on Twitter and then become like little grass fires that turn into bonfires," she said.

Mentions of Houston peaked at a mere 511 on January 26, while mentions of Prince Philip reached their peak at 8702 on the same day.

Among mainstream news sites, Facebook, forums and blogs, Twitter hosted an overwhelming 75.6 per cent of mentions including Prince Philip.

However it was Facebook where Sir Angus received most mentions, a total of 40.7 per cent.

Ms Gloria said #knightmare was the most highly-mentioned word used in the online discussion around the issue.

"It's just whatever catches the imagination of the collective," said Ms Gloria.

"The whole thing about #knightmare is that it's such a clever pun, so everyone just jumps on it. It becomes very organic."