mystery bulbs

I had these in a pot until recently. They didn't flower but have been growing strongly (the leaves are ridiculously long) the last couple years so when I was emptying my pots recently I was curious to see what they were. Having removed them I still don't know! I assume they are tulips but I'm not sure. They didn't get enough sun maybe? I didn't add anything to this photo to indicate scale but the single bulb in the middle is huge. On either side are clusters of similar bulbs. So why haven't these flowered and why did one grow so big and 2 others grow into a cluster of bulbs?