LONDON—British police arrested a man on Tuesday in connection with the theft of gold rosary beads carried by Mary Queen of Scots to her execution in 1587, among items worth more than £1 million ($1.37 million) stolen from a castle in the south of England. Mary, a Roman Catholic, was ousted from the Scottish throne then imprisoned, accused of treason, and executed on the orders of her Protestant cousin Elizabeth I of England, a series of events that loom large in the British imagination. Several other historic treasures including coronation cups as well as gold and silver items were among the loot taken from a display cabinet at Arundel Castle in the county of West Sussex in May. Sussex Police said a 45-year-old man was arrested on suspicion of burglary on Tuesday in Eckington, Worcestershire, central England. The man remains in custody for questioning. “Our investigation into the Arundel Castle …