In chess, a king walk, also known as a steel king (Dutch: wandelkoning, literally "wanderking") or fighting king, refers to occasions where the king travels up the board, often in the context of its active involvement in the mating attack against the opposing king. This is a highly unusual occurrence since the safety of the king is considered paramount, and players are recommended to keep them out of harm's way, at least until the endgame. Nevertheless, in contrast Wilhelm Steinitz, often known as the father of modern chess, was renowned for his maxim that "the king is a fighting piece". Dutch chess historian and author Tim Krabbé has documented over one hundred such games.

Because of the rarity of such tactics, those which reap rewards for the attacking player often have brilliancy prizes bestowed upon them. Perhaps the most famous in recent history, where Nigel Short defeated Jan Timman in Tilburg in 1991, was voted as one of the hundred greatest chess games in a list compiled by FM Graham Burgess, and GMs John Nunn and John Emms.

A monarch is the person who leads a monarchy. This is a form of government in which a state or polity is ruled or controlled by an individual who typically inherits the throne by birth and rules for life or until abdication. Monarchs may be autocrats (absolute monarchy) or ceremonial heads of state who exercise little or no power or only reserve power, with actual authority vested in a parliament or other body (constitutional monarchy).

The word monarch is derived from the Greek μονάρχης (from μόνος, "one/singular," and ἄρχων, "leader/ruler/chief") through the Latin: monarcha (mono: "one" + arch "chief") which referred to a single, at least nominally, absolute ruler. In current usage the word monarchy generally refers to a traditional system of hereditary rule, as elective monarchies are rare in the modern period (though they do still exist in Vatican City, Andorra and Malaysia).

Most states have at most one monarch at any given time, although a regent may rule when the monarch is a minor, not present, or otherwise incapable of ruling. Two monarchs have ruled simultaneously in some countries, as in the ancient Greek city-state of Sparta or the joint sovereignty of spouses or relatives (e.g. William and Mary of Kingdom of England and Scotland, Peter and Ivan of Russia, Charles and Joanna of Castile, etc.).

Walking (also known as ambulation) is one of the main gaits of locomotion among legged animals, and is typically slower than running and other gaits. Walking is defined by an 'inverted pendulum' gait in which the body vaults over the stiff limb or limbs with each step. This applies regardless of the number of limbs - even arthropods with six, eight or more limbs.

The word walk is descended from the Old English wealcan "to roll". In humans and other bipeds, walking is generally distinguished from running in that only one foot at a time leaves contact with the ground and there is a period of double-support. In contrast, running begins when both feet are off the ground with each step. This distinction has the status of a formal requirement in competitive walking events. For quadrupedal species, there are numerous gaits which may be termed walking or running, and distinctions based upon the presence or absence of a suspended phase or the number of feet in contact any time do not yield mechanically correct classification. The most effective method to distinguish walking from running is to measure the height of a person's center of mass using motion capture or a force plate at midstance. During walking, the center of mass reaches a maximum height at midstance while during running, it is at a minimum. Definitions based on the percent of the stride during which a foot is in contact with the ground (averaged across all feet) of greater than 50% contact corresponds well with identification of 'inverted pendulum' mechanics and are indicative of walking for animals with any number of limbs, although this definition is incomplete. Running humans and animals may have contact periods greater than 50% of a gait cycle when rounding corners, running uphill or carrying loads.