Having secured promotion from SWALEC Division 4 East in 2007 they finished mid-table in Division 3 South East the following season. But then came successive relegations as they plummeted back down to Division 5 South East.
There was consolidation last year, but the 2011/12 season has brought real success for the fittest team in their division. Having lost two of their opening six games, to Cilfynydd (13-8) and Clwb Rygbi (27-17) both at home, they went 18 games without defeat to clinch the title by six points from Cilfynydd.
"Winning the title means a huge amount to the club and it has been a good year for us after coming close last season. We have great camaraderie and we've gone 18 matches unbeaten since October," said player-coach Adam Staniforth.
"We've played with greater consistency and been lucky with injuries. That has given us a more solid squad than in the past. Mike Jones has done a lot of work on the team's fitness and he made us the fittest team in the league.
"And a lot of the work our head coach Mike Pugsley has put into place in the pack has also come to fruition. This is my second season at the club and I initially came to coach.
"But after four or five games they asked me to play and it's gone from there. We should be OK next season, although we'll need to pick up one or two players. There isn't a huge gulf in the leagues at this level, but we've got a few guys who are hanging up their boots and we've always got the problem of students who finish their courses and head home."
Staniforth spent six years as a semi-pro and professional player at Exeter Chiefs, and also played at Launceston and Clifton, and is relishing the chance to cut his teeth as a coach at Old Illtydians.
"It has been pretty interesting and you go to lots of interesting places where there's plenty of passion for the game. I absolutely love it and I'm really glad I joined the club - I wouldn't want to play for any other team in Cardiff now," said the 30-year-old outside half, Staniforth.
"We didn't lose a game away from home all season and we've got the toughest defence in the league, averaging 10 points per game. The forwards aren't the biggest around, but they really put in a shift and just love it."
SWALEC NATIONAL LEAGUE CHAMPIONS 2011 / 12
Division 1: Ebbw Vale
Division 2: Ystrad Rhondda
Division 3: Garndiffaith
Division 1: TATA Steel
Division 2: Glynneath
Division 3: Haverfordwest
Division 4: Llanelli Wanderers
Division 5: Fishguard & Goodwick
Division 6: Pontrhydyfen
Division 1: Caernarfon
Division 2: Dolgellau
Division 3: Shotton Steel
Division 6: Glyncoch
Division 3: Llanishen
Division 4: Porth Harlequins
Division 5: Old Illtydians
Division 5: Bryncethin
Division 3: Maesteg Harlequins
Division 4: Maesteg Celtic
Division 5: Penlan