The leaders of North Lincolnshire, North East Lincolnshire and Lincolnshire County councils, Coun Rob Waltham, Coun Philip Jackson and Coun Martin Hill, hosted the event to mark Lincolnshire Day and strengthen ties across the whole of the historic county.
It is hoped the civic celebration will become an annual Lincolnshire Day tradition.
The event also saw the winners of the Greater Lincolnshire Menu competition announced.
The competition was launched earlier this year to showcase the wealth of amazing food producers in the county and the winners included sautéed Lincolnshire sausage, black pudding and chorizo on sourdough, from The George, in Kirton in Lindsey.
Coun Martin Hill, leader of Lincolnshire County Council, said: “Lincolnshire has a rich heritage and culture, of which we’re all proud. And it’s that shared pride that has brought us together to celebrate Lincolnshire Day.
“As well our great history, we come together to reinforce our commitment to Lincolnshire's present, improving the lives of our residents, supporting our local businesses and boosting tourism and investment, and to our prosperous future.”
Coun Philip Jackson, leader of North East Lincolnshire Council, explained: “We are proud of what we are achieving in North East Lincolnshire alone, but working together as part of Greater Lincolnshire, we could do so much more to deliver our collective green agenda and economic aspirations and make the county a place where people want to live.”
Coun Rob Waltham, leader of North Lincolnshire Council, added: “This is the first time we have come together to celebrate Lincolnshire Day and it is a real privilege to be able to host the occasion.
“Lincolnshire Day is about showcasing all that is great in our region, so it is fitting that we meet at Normanby Hall – one of many fantastic tourist attractions our county has to offer – to plant a tree that will be enjoyed by generations to come.”