Changed a light fitting, Now another trip switched has stopped working.

Hey everyone, I was switching out the light fittings in the front room of our flat (the one it came with is disgusting!) and I put the new one in like for like. There is one cable from the ceiling with a Blue (N), a Brown (L), and a Green/Yellow (E) wire coming from it. These were going into connector blocks fitting corresponding Blue, Brown and Green/Yellow wires to the old fitting. I took this out, fitted a new connector block, and connected like for like wires again for Live, Neutral and Earth and secured the fitting. I flip the switch. TADA! New lights work. Great. I then wander to the back of the flat and turn my bedroom light on... nothing, try the bathroom, nothing... second bedroom... nothing. The hallway works (weirdly because I swear it was on the same breaker switch as the back rooms!) When looking at the breaker BEFORE I started, I have 3 switches. One did the front of the flat, One did the back (and hallway I'm pretty certain), and the 3rd didn't seem to do anything. Either way I switched them all off.