32 B.C.: during the age of Chinese Emperor Ch'eng Ti, bamboo poles were erected with a silken net stretched between to form a goal.

1681: A game was arranged between the servants of the King, and those of the Duke of Albemarle. The doorways of two forts were used as goals, and players attempted to score by driving the ball through one of the doorways.

In the 17^th century, a goal consisted of two upright poles with nothing between them. Tape was later introduced, attached to the top of each upright stretching across the width of the goal. Prior to the 1800s, a goal would consist of any fixed object such as houses or trees, at any distance apart, from a few yards to many miles! 
Players were allowed to throw the ball into the goals.

1801: Joseph Strutt describes the composition of a goal structure as:

The goal is usually made with two sticks driven into the ground two or three feet apart.

1832: Uppington School rules:

A goal is scored whenever the ball is forced through the goal and under the bar, except it be thrown by the hand.

1848: The Cambridge rules:

Goal is when the ball is kicked through the flag-posts and under the string.

1861: The Eton rules:

The goal-sticks are to be 7 feet out of the ground and the space between eleven feet. A "goal" is gained when the ball is kicked between them, provided it is not above them.

1863: There is no mention of a bar in the Cambridge University rules:

The goals shall consist of two upright poles at a distance of 15 feet from each other.

A goal is obtained when the ball goes out of the ground by passing between the poles or in such a manner that it would have passed between them had they been of sufficient height.

In other words, because there was no crossbar, there was no height restriction for a goal to be scored.

The Football Association show the structure to be:

The goals shall be defined by two upright posts, 8 yards apart, without any tape or bar across them.

1865: Tape is introduced "extending from one goal-post to the other at a height of 8 feet from the ground" under which the ball had to be kicked to score a goal.

1866: In February, the Football Association introduce tape by decreeing that: "The goals shall be upright posts, eight yards apart, with a tape across them, eight feet from the ground". This heralded the standard goal size that has remained unchanged until the present day.

1870: In place of tape fixed eight feet from the ground, the Sheffield rules introduce – "a bar, 9 feet from the ground….. When the ball is kicked over the bar of the goal, it must be kicked out by the side behind whose goal it went, within 6 yards from the limit of their goal".

1875: The cross-bar makes its first appearance into the Football Association rules in 1875 when 'bars' become obligatory.

1877: The Football Association and the rival Sheffield Association agree on a set of rules, and an alteration was inserted "…with tape or bar across them, eight feet from the ground."

1882: Following a conference by the four British Associations in December, crossbars are made obligatory, and tapes were finally abolished.

1891: Goal nets were suggested by a Birmingham man, and later patented and manufactured by J Brodie of Liverpool, a Rugby player who gave the idea to Bob Lythgoe a former Liverpool goalkeeper. Brodie was talked into patenting the idea and Bolton were the first club to trial the nets although only at one end strangely it was a game against Notts Forest on New Years Day 1891. It still took some time before nets were used by all clubs due to the FA wanting a fair price eventually they settled on a figure of £3, 12s 6d. They were first used in an important match between the North v South in January 1891. The first Cup Final to use nets was played at the Oval in 1892 between West Bromwich Albion and the Villa. Even in the modern Laws, nets are still not a compulsory item, but are mentioned as a necessity in nearly all competition rules.

1895: Detailed measurements of the goal framework are introduced. "The maximum width of the goal-posts and the maximum depth of the cross-bar shall be 5 inches".

1938-1939: It was finally settled, that it was the internal edges (inside measurements) of the goal framework, which constituted the actual goal. The maximum (5 inch) width of the boundary lines came soon after, and this resulted in a similar depth and width given for the goal-posts and the cross-bar. The Referees' Chart Law 1 introduces the following:

….the lower edge of which shall be 8ft. from the ground. The width and depth of the goal-posts and the width and depth of the cross-bar shall not exceed 5 inches.
Goal-posts should be painted white.

The "Advice to players" section of the Referees' Chart, contains the following:

Goalkeepers, in an effort to save a shot or to get hold of the ball, sometimes intentionally seize the bar and pull it down. Such action ranks as misconduct.

The "Advice to Referees" section of the Referees' Chart, contains the following:

Never allow tape or any other substances not of a rigid nature to be used instead of a cross-bar.

The actual position of the ‘real’ goal is formed by the outer back edges of the goal-posts, the cross-bar and the goal line that runs between the goal-posts. Yet the goal framework uprights actually sit within the field of play, by interrupting the goal line - which should, according to the older version of the Law, go from corner flag to corner flag. This was obviously a mute point with the early Law makers, and gives emphasis to the word "on" in the Law 1 wording: "Goals must be placed "on" the centre of each goal line".

1950s: The Referees' Chart and Players Guide to the Laws of the Game Law 1 (Decision of the International Board), now state that:

….goal-posts and the cross-bar may be square, rectangular, round, half-round or elliptical in shape.

A square framework offers a true representation of the 8 yards by 8 feet goal dimensions, but there are now many goal-post and cross-bar designs shaped almost like an egg. If you consider these designs geometrically, they are not in accordance with the Law. The distance measured between two elliptical-shaped posts correctly positioned "on" the goal line, and taken from various positions around the outer ('C' shaped) edges will give varying distances larger than the regulation space of 8 yards by 8 feet. The exaggerated bevelled edges of elliptically shaped posts and cross-bars, will also give the ball more than 8 yards by 8 feet to enter if it approaches from an acute angle.

1967-1968: The following is added into Law 1:

Goal-posts and cross-bars must be made of wood, metal or other approved material as decided from time to time by the International F.A. Board. Goal-posts and cross-bars made of other materials and in other shapes are not permitted.

A list of approved materials can be obtained from: FIFA, PO Box 85,8030 Zurich, Switzerland.

1994-1995: The most important element of cross-bar "safety" makes its first appearance in Law 1, and the following sentence is introduced into paragraph 6 (The Goals):

For safety reasons, the goals, including those which are portable, must be anchored securely to the ground.

This was in response to a number of fatalities occurring due to accidents involving the cross-bar - particularly in games where young children were involved.

1996-1997: Following the complete rewrite of the Laws in season 1997-1998, this year (1996-1997) sees the last mention of the following International Board Decision No. 8, paragraph.

In a friendly match, by mutual consent, play may be resumed without the cross-bar provided it has been removed and no longer constitutes a danger to the players. In these circumstances, a rope may he used as a substitute for a cross-bar. If a rope is not used and the ball crosses the goal-line at a point which in the opinion of the Referee is below where the cross-bar should have been he shall award a goal.

A goal structure without an integral cross-bar will greatly weaken the framework. The paramount concern for the Referee, must always be with the safety of the players, and allowing a game to proceed without a cross-bar (even if it is a friendly game) would not be a wise decision in today's climate of litigation.

1997-1998: Equivalent metric measurements are introduced into the newly rewritten Laws:

The distance between the posts is 7.32 m (8 yds) and the distance from the lower edge of the crossbar to the ground is 2.44 m (8ft).

A new specific paragraph entitled 'Safety' is introduced into Law 1:

Goals must be anchored securely to the ground. Portable goals may only be used if they satisfy this requirement.

New International FA Board Decisions are introduced, stating that:

No kind of commercial advertising, whether real or virtual, is permitted on the field of play and field equipment……..In particular, no advertising material of any kind may be displayed on goals, nets, flagposts or their flags. No extraneous equipment (cameras, microphones, etc.) may be attached to these items.

It is also worth mentioning here, the following International FA Board Decisions Law 1 paragraph, that is a progression of the wording that originally appeared in the 1938-1939 season:

If the crossbar becomes displaced or broken, play is stopped until it has been repaired or replaced in position. If a repair is not possible, the match his abandoned. The use of rope to replace the crossbar is not permitted. If the crossbar can be repaired, the match is restarted with a dropped ball at the place where the ball was located when play was stopped.

The words goal-post and cross-bar have their hyphens removed and become goalpost and crossbar.

2000 Safety: The English Football Association launched a major campaign in August 2000 aimed at highlighting goalpost safety throughout grassroots football. The drive comes after the deaths of nine children in accidents involving goalposts over the last few years. The principles launching this campaign were:

"Check It" - make sure goalposts are in good condition and properly constructed. Home-made goalposts should never be used - they do not have built-in safety features and may be particularly hazardous for younger players.

"Secure It" - goalposts of any size must be securely anchored to the ground. Portable goalposts must be pinned or weighted down to prevent them toppling forward, and should be removed from the pitch when not in use and stored securely.

"Test It" - adults should test the goalposts to make sure they are stable by exerting a downward force on the crossbar, backward force on both upright posts and forward force on both upright posts.

"Respect It" - goalposts should only be used for their intended purpose; in particular, children should not swing on them.