Battery issues help please

Morning

300tdi auto 1997
Removed battery before going away for 2 weeks on refitted today correctly and have no power. Battery is good and have tried to jump start as a second measure still nothing no lights on dash central locking not working etc etc.

Just a key to open doors no fob alarm or immobiliser.

Any thoughts guys?

Many thanks as always

Andy

First off, I would recheck carefully that you've done everything properly, even to the point of undoing the job completely and starting again. Check that the battery is installed the right way round; some batteries have the terminal posts on the corners which is almost impossible to put in the wrong way round, but some other batteries have the terminals at either end of the centre line and they need a bit more care when refitting.
Check also that you've reconnected all the other cables to the positive terminal. Very often there's one large cable to power the starter motor dirctly and the at least one smaller cable connecting to the rest of the vehicle. These smaller cables can often be missed or even stuck under the battery where it can't even be seen.
Once you've done all that, check that the joints between the cables and the terminals are intact, moving them can cause old soldered joints to fail. This applies to both the positive side as well as to the earth side of the circuit.
It's unlikely that disconnecting the battery is going to blow any fuses, but a check of the main fusebox under the bonnet could show up a fault.