Paralympic champion Sam Hynd led a British clean sweep in the S8 400m freestyle on day three of the European Swimming Championships in Berlin.
The world record holder took gold, with younger brother Oliver winning silver and Tom Young bronze.
Heather Frederiksen took gold in the S8 400m freestyle, and Matt Walker defended his S7 50m freestyle title.
Hannah Russell, 14, won her first international medal by taking bronze in the S12 100m butterfly.
Russell broke her British record with a time of one minute 11.83 seconds.
Hynd, who clocked 4:29.18, said: "It was a fantastic race, it went to plan. It felt really good, I'm just happy I kept my title. It's a good time to be hitting."
Frederiksen, the Paralympic champion over 100m backstroke, recorded a time of 4:58.80 to add to her 100m backstroke gold and 50m freestyle silver.
"It was good to go out there and swim fast and comfortably and break five minutes, so I'm really pleased with that," she said.
The women's 34pt 4x100m freestyle relay quartet of Louise Watkin, Lauren Steadman, Susie Rodgers and Claire Cashmore took gold in a European record of 4:27.53.
And Rodgers broke her British record with a time of 33.99 seconds in the S7 50m freestyle to win silver.