Great Britain have achieved their highest Olympic gold medal total for 104 years after victory in the team dressage.

Gold for the dressage team at Greenwich means Britain have won 20 golds, beating a haul of 19 at the 2008 Games.

Earlier in the day, Alistair Brownlee won the triathlon and his brother Jonny took bronze, while Nick Dempsey claimed windsurfing silver.

That takes the overall total to 44 medals, three short of the 2008 Games.

Further medals could follow on Tuesday in cycling.

But in athletics, Phillips Idowu failed to reach the triple jump final – ending his medal hopes.

Brotherly love

Alistair Brownlee on brother Jonny (right), who collapsed at the finish: “Jonny is fine, triathlon is a tough sport and we have both been in that position. He was probably right on the edge at the end as is usual.”

Britain’s best gold total since the London Olympics of 1908 came courtesy of a dressage team of Carl Hester, Laura Bechtolsheimer and Charlotte Dujardin.

And a further five guaranteed medals to come has made the 2012 Olympics the most successful of modern times.

Four years ago, Britain did not reach 19 golds until the final Saturday when James DeGale earned boxing victory in the men’s middleweight division.

But Team GB are already guaranteed four further boxing medals after Anthony Joshua, Anthony Ogogo, Luke Campbell and Nicola Adams reached the respective semi-finals of their divisions.

And with another silver guaranteed in men’s sailing, Britain have effectively reached UK Sport’s minimum target of 48 with more than five days of competition left at the London Olympics.

Victory for Alistair Brownlee, 24, was Britain’s first Olympic triathlon title and the world champion finished the Hyde Park race draped in a union jack in one hour 46 minutes and 25 seconds.

His brother Jonny, 22, was third despite being penalised 15 seconds for boarding his bike too soon and the medal ceremony was delayed after he collapsed with exhaustion. But Alistair said his brother was fine and had just suffered from a tough race.

“It feels a bit underwhelming because Jonny has just collapsed,” Alistair said of his historic achievement. “It feels fantastic and the race was unbelievable. The crowds, I don’t think I’ve ever come across anything like that. My ears were stinging – it was amazing.

“I’m massively proud. It’s been talked about so much that we haven’t won triathlon gold and favourites don’t win, so the pressure was stacked up but to get two of us on the podium you couldn’t ask for any more.

“As much as I said it was just like any other race, it’s the Olympics so it wasn’t. I was so excited to start and I was like a kid at Christmas when I woke up this morning.”

In cycling, Sir Chris Hoy will be aiming to win a sixth Olympic gold when he goes in the keirin, while Victoria Pendleton will compete in the individual sprint . Laura Trott is also in contention in the omnium.

If Hoy succeeds he will overtake Sir Steve Redgrave’s record for the most GB Olympic gold medals and Pendleton would become Britain’s most decorated female Olympian.

In athletics, high jumper Robbie Grabarz and discus thrower Lawrence Okoye also have medal chances in their  respective finals at the evening session in the Olympic Stadium, starting at 19:00 BST.