The move back south arrived only five months after Gayle arrived at Ibrox for a similar fee from Wimbledon.

He failed to make an impact in the Scottish Premier League, but Rangers manager Dick Advocaat has refused to accept that the original deal had been a mistake.

"No, not at all. I said at that point we needed a striker and we got the same money back, so it was a bargain," said Advocaat.

Gayle was brought in as Rangers desperately attempted to hold on to their title but played only four times and failed to score as Celtic charged to the championship.

Seventh summer signing

The 30-year-old Jamaican international will attempt to re-ignite his career back in the First Division under Gianluca Vialli at Vicarage Road after signing a two-year deal.

"I just wanted to do it for the Rangers supporters and I want to thank them for their support while I was there.

"I am now looking forward to continuing my career at Watford."

Gayle becomes Vialli's seventh summer signing.

He began his career as a winger at Brentford. But, after nearly 200 appearances for the Bees, he joined Wimbledon for �250,000 in 1994.

Third player to leave

Then manager Joe Kinnear converted him to a striker and Gayle went on to make almost 300 appearances for the South London club.

During that time, he gained 15 caps for Jamaica, the highlight of his international career coming when he played at the 1998 World Cup finals in France.

Gayle became the third player to leave Rangers in a week, 20-year-old winger Seve Carson having signed for Dundee United for �150,000 the previous day.

Young striker Peter MacDonald had moved to St Johnstone for �125,000 in time to debut for the Perth club on Saturday.

Winger Allan Johnston is also still hopeful of a �1m move to Sunderland.