A mish-mash of Dublin (Dubhlinn) medieval history ...the Viking invasion (9th century), Christchurch Cathedral (1028), King Brian Boru (941), the round tower in Clondalkin (776), Dublin castle (1228), Strongbow's tomb (16th century) and St Patricks Cathedral tower (1220).
detail: Dublin Castle
 
detail: Viking, King Brian Boru, Christ Church Cathedral Arch
detail: Strongbow's Tomb
Full Illustration
detail: St. Patrick's Cathedral Tower
Strongbow pencil