Title: Bed
Content:  were used in high society in France until the end of the Ancien Régime. The earliest of which mention has been found belonged to Charles the Bold. They had curtains over a light framework, and were in their way as fine as the stationary beds. Iron beds appear in the 18th century; the advertisements declare them as free from the insects which sometimes infested wooden bedsteads. Elsewhere, there was also the closed bed with sliding or folding shutters, and in England—where beds were commonly quite simple in form—the four poster was the usual citizen's bed until the middle of the 19th century.
Title: Bed
Content:  In the 18th century feather pillows were first used as coverings in Germany, which in the fashions of the bed and the curious etiquette connected with the bedchamber followed France for the most part. The beds were a la duchesse, but in France itself there was great variety both of name and shape. The custom of the "bed of justice" upon which the king of France reclined when he was present in parliament, the princes being seated, the great officials standing, and the lesser officials kneeling, was held to denote the royal power even more than the throne. Louis XI is credited with 
Title: Bed
Content:  first use and the custom lasted until the end of the monarchy. In the chambre de parade, where the ceremonial bed was placed, certain persons, such as ambassadors or great lords, whom it was desired to honour, were received in a more intimate fashion than the crowd of courtiers. At Versailles women received their friends in their beds, both before and after childbirth, during periods of mourning, and even directly after marriage—in fact in any circumstances which were thought deserving of congratulation or condolence. During the 17th century this curious custom became general, perhaps to avoid the tiresome details of etiquette. Portable 
Title: Polish bed
Content:  possibly first observed at the Royal Castle in Warsaw, at the time when Ottoman styles were fashionable across Europe. They were popularized in France by Polish-born queen Marie Leszczyńska, who married Louis XV of France in 1725. Hence, it became a principal piece of the so-called Louis XV furniture. These richly decorated rococo beds were generally designated for the wealthier upper classes and aristocracy that resided in palaces, however, canopies were also popular in many common homes (the warmth of the curtains was functional). The French propagated the design as lit à la polonaise. Polish beds dating back to the period can be found in museums, most famous being the Palace of Versailles in France. The polonaise should not be confused with the lit à la Duchesse where the canopy is only supported from one end.
Title: Bed base
Content:  Plank beds raised above the floor on trestles were used in Europe, but use declined in the 1600s.
Title: Bed
Content:  In the 17th century, which has been called "the century of magnificent beds", the style a la duchesse, with tester and curtains only at the head, replaced the more enclosed beds in France, though they lasted much longer in England. Louis XIV had an enormous number of sumptuous beds, as many as 413 being described in the inventories of his palaces. Some of them had embroideries enriched with pearls, and figures on a silver or golden ground. The great bed at Versailles had crimson velvet curtains on which "The Triumph of Venus" was embroidered. So much gold was used that the velvet scarcely 
Title: Bedding
Content:  stuffed with straw and feathers and then covered with silks, velvets or satin material. Embroidered canopies and ornamental hangings as well as the advent of the featherbed led to beds becoming extremely expensive, often willed down from generation to generation. In the 18th century, Europeans began to use bed frames made from cast iron, and mattresses that were made of cotton. In the 19th century the bed spring was invented, also called the box spring. In the 20th century United States, consumers bought the inner spring mattress, followed in the 1960s by the water bed (originating on the West Coast), and adoption of Japanese-style futons, air mattresses, and foam rubber mattresses and pillows.
Title: Canopy bed
Content:  The canopy bed arose from a need for warmth and privacy in shared rooms without central heating. Private bedrooms where only one person slept were practically unknown in medieval and early modern Europe, as it was common for the wealthy and nobility to have servants and attendants who slept in the same room. Even in very modest homes, it was not uncommon to hang a simple curtain across a room to shield the bed from cold drafts and create a sense of division between living space and sleeping space. From the 16th century on, ornately carved bed frames and expensive textiles became popular. In pre-Republican China, until 1911, the family's canopy bed was the most important piece of household furniture, and often part of the bride's dowry. As signifiers of status, these beds were often intricately decorated with auspicious motifs, particularly relating to fertility, longevity and a happy marital union. In Germany, Frommern was the world capital of furniture in the time of Wirtschaftswunder. In Frommern a line of high polished industrial production take up the ideas of the royal Hofebenist. In the Haus der Volkskunst the traditional Himmelbett is used as a hotel bed.
Title: Louis XV furniture
Content:  Under Louis XV the bedroom was a place of ceremony; the formal awakening of the King in his bed chamber (even if he had actually slept elsewhere) was a formal event, attended by members of the Court and visitors to the Palace. The form of the bed and its covering evolved under Louis XV. Early beds had four posts and a canopy suspended from a rectangular form on top. Under Louis XV, the Lit à la polonaise (Polish bed) appeared, with a canopy suspended from a crownlike structure; and the Lit à la Duchesse, where the canopy was supported only from one end. The bed was usually separated from the rest of the room by a balustrade, and stools were arranged outside the balustrade for the Court to witness the formal awakening. The famous Encyclopédie of Denis Diderot and Jean le Rond d'Alembert (1751–72) included images of beds à la Polonaise, and à la Turque (a more ornate and exotic version of the Duchesse) and a bed placed into an alcove. (Volume 8, pg. 216).
Title: Bed
Content:  were received there. The 14th century is also the time when feather beds became highly prized possessions. In the 15th century beds became very large, reaching 7 to 8 ft by 6 to 7 ft. The mattresses were often filled with pea-shucks, straw, or feathers. At this time great personages were in the habit of carrying most of their property about with them, including beds and bed hangings, and for this reason the bedsteads were for the most part mere frameworks to be covered up; but about the beginning of the 16th century bedsteads were made lighter and more decorative, since the lords remained in the same place for longer periods.

Question: when did beds become popular in france and germany?
Answer: the 12th century.