1) Armor-plated warship 2) Armor-plated warships 3) Bygone warship 4) Cromwell 5) English Civil War soldiers 6) Full general 7) General 8) National leader 9) Oliver cromwell 10) Solon 11) Statesman 12) The Virginia and the Monitor 13) Warship Found on https://www.crosswordclues.com/clue/ironsides
I'ron·sides' noun A cuirassier or cuirassiers; also, hardy veteran soldiers; -- applied specifically to Cromwell's cavalry. Found on http://www.encyclo.co.uk/webster/I/96
Ironsides was Second World War British army slang for a Bedford 30-cwt lorry converted into an armoured car by the addition of boiler plate on the sides. Found on http://www.probertencyclopaedia.com/browse/ZI.HTM