Rushdie returned to Britain to be formally invested as a "Companion of Honour" -- an exclusive royal accolade whose ranks are capped at 65 members.

Speaking after the ceremony at Windsor Castle outside London, the 75-year-old writer said it "took a while" but that he had resumed working.

Asked when he expects to complete his next book, he said: "Oh, I'll let you know."

The award-winning novelist, a naturalised American who has lived in New York for 20 years, lost sight in one eye after being repeatedly stabbed on stage last August while speaking at an arts centre.

In February, around the release of his latest novel "Victory City", the writer said in his first interview since the attack that he had faced a lot of difficulty writing and was suffering from post-traumatic stress.

Wearing glasses with a black lens over his right eye, Rushdie said at Windsor that it was a "great honour" to be recognised for a "lifetime" of work, following his investiture by Princess Anne.

The "Midnight's Children" author was awarded a British knighthood in 2007.

Rushdie has been the victim of repeated death threats and attempts on his life since the publication of his 1988 novel "The Satanic Verses", which was declared blasphemous by Iran's supreme leader.