Sony Ericsson W810i. Got it in 2007, I think. When it started to die on me in late 2009 i replaced it with an iPhone 3G, which was my first apple phone. It was also my last apple phone as I hated how locked down everything was.
EDIT: I just remembered I had a secondary dumbphone around 2012 or thereabouts. It was a dual SIM nokia of some sort that I used mainly as a backup phone in case my main ran out of battery while I was on the move.
I found mine here, I'm sure you'll recognize yours: https://m.gsmarena.com/sony_ericsson-phones-19.php