The Lord Mayor of Sheffield has welcomed civic dignitaries from across England's largest county to celebrate Yorkshire Day.
Anne Murphy joined mayors from across the traditional North, East and West Ridings for a parade through Sheffield city centre for a service in the cathedral.
The snaking procession, led by the City of Sheffield Pipe Band, confused some shoppers - clearly unaware of the significance of August 1 - with one woman asking reporters if it was St Patrick's Day and another saying: "That's an impressive wedding for somebody."
But the Lord Mayor said it was a proud day for Sheffield and Yorkshire, saying: "I don't think there's any harm in celebrating one day a year for Yorkshire."
Mrs Murphy said: "It's fabulous to be celebrating Yorkshire Day in Sheffield. It's a great honour. Happy Yorkshire Day to everybody in Yorkshire."
She said the mayors, who gathered in the ornate surroundings of the Town Hall, were joined by Yorkshire folk in New Zealand for a Facetime Live stream to mark the day.
She added: "I think it's important to celebrate Yorkshire. It's an opportunity for all the Yorkshire people to get together and talk about all the positives that happen in Yorkshire. It's a fabulous county and we need to celebrate it.
"And I don't think there's any harm in celebrating one day a year for Yorkshire."
The official events in the centre of Sheffield were mirrored by scores of others across the county.
Halifax is marking Yorkshire Day with the reopening of the restored Grade I-listed Piece Hall, the only surviving 18th-century cloth hall in the UK and one of only a handful across Europe.
Xscape Yorkshire in Castleford is hosting a unique Yorkshire vending machine which only dispenses produce from the county, including Yorkshire puddings, Yorkshire Tea and Seabrook Crisps.
One of the best known Yorkshiremen, Geoffrey Boycott, will be the special guest at a family fun day in support of the Yorkshire Air Ambulance at Wentbridge House, near Pontefract.
Another event which has become a traditional part of the day is the annual Yorkshire pudding tossing competition and straw bale race at York Maze.
In Otley, 21 pubs will be temporarily changing their names to reference Yorkshire-born celebrities, from Sean Bean and Dame Judi Dench to local cycling champion Lizzie Deignan.
Each pub will get a name in the draw and then spend the next 12 months tracking down the famous face to persuade them to take a drink in their named pub on Yorkshire Day 2018.
Yorkshire Day was first celebrated by the Yorkshire Ridings Society on August 1 1975.
The society was formed a year earlier to campaign for the traditional boundaries of Yorkshire which were substantially altered by a radical mid-1970s local government reorganisation.
According to the society, August 1 was chosen as it was the date of the Battle of Minden in Germany in 1759.
The battle is marked by the Army allowing soldiers to wear roses in their caps, and Yorkshire regiments have traditionally sported the white rose.
One of the key features of the day is the reading of the Yorkshire Declaration of Integrity.
The declaration is usually read in York in all the languages used in Yorkshire since its earliest known reference in Anglo Saxon times - Old English, Latin, Old Norse and modern English.
This year's declaration will refer to "within these boundaries of 1,142 years standing", which is a reference to its Viking foundation in 875AD.
The parade of mayors began in 1985.
Yorkshire Day celebrations began at the weekend in Uppermill - just over the modern border in Greater Manchester.
The cluster of villages that make up Saddleworth - including Uppermill - were traditionally part of the West Riding until the 1974 local government reorganisation.