“Game of Thrones” swoops back onto screens March 31 like a marauding dragon. HBO’s hit series based on George R.R. Martin’s best-selling fantasy novels draws inspiration from British history and has filmed in locations across the UK, many of which are easy to visit.

Ice zombies and telepathic mega-wolves aside, the Song of Ice and Fire saga has roots in England’s 15th-century Wars of the Roses, fought between the Yorks and Lancasters. Martin re-imagined these dueling clans as the rugged Starks and wealthy, blinged-out Lannisters (most of them now played on TV by British actors, in keeping with the way American producers usually imagine fantasy realms).

In a column for British newspaper The Guardian, Damien G. Walter observed the similarities. “One throne unifies the land but great houses fight over who will sit upon it,” he wrote. “With no true king the land is beset with corrupt, money-grubbing lords whose only interest is their own prestige. Two loose alliances of power pit a poor but honourable North against a rich and cunning South.”

Among other connections, fans point to echoes of King Edward IV in the lusty, brawling warrior-king Robert Baratheon, who grows overindulgent with middle age. Cersei, the character’s conniving Lannister wife, may be modeled on the firebrand Margaret of Anjou. She fueled the Wars of the Roses while trying to maintain her family’s hold on the crown as her husband, Henry VI, battled frequent bouts of insanity.

Named for the badges of each house (with a red flower for Lancaster and a white one for York), these conflicts continued for almost a century. The situation went critical at Ludlow Castle in Shropshire, where the Lancastrian army routed the Yorkists, whose leaders fled abroad. The war raged from The Tower of London to Wales’ Raglan Castle and Tewkesbury Abbey in Gloucestershire, which still holds a communion service for the fallen each May 4. BBC History Magazine provides an excellent guide for enthusiasts, while Travel Editions runs a two-night tour on Richard III and the Wars of the Roses ($455, next available dates: August 9 and September 27, 2013).

Martin’s version of Hadrian’s Wall, which the Romans built across the country from Cumbria to Tyne and Wear, is a 700-foot, 300-mile barricade of ice. Now one of northern England’s most popular tourist destinations and a World Heritage site, Hadrian’s Wall attracts hikers and bicyclists as well as history buffs.

Sets and a touring showcase

The atmosphere of medieval Britain saturates the “Game of Thrones” novels, so it’s no surprise that HBO turned to the UK for backdrops when it came to filming. Scotland’s Doune Castle doubled as Winterfell — the stronghold of the noble, foolhardy Starks — in the first season. But before it starred in this sex- and violence-drenched saga, the castle was known for its role in a whimsical spoof: Visitors may find the 14th-century fortress familiar from “Monty Python and the Holy Grail” ($7.60 adult, $4.60 child). In fact, comedian and Monty Python regular Terry Jones narrates a free audio tour that highlights Spamalot, African sparrows and other in-jokes from the 1975 classic.