Castles continued to grow in military sophistication and comfort during the 12th century, leading to a sharp increase in the complexity and length of sieges in England. While in Ireland and Wales castle architecture continued to follow that of England, after the death of Alexander III the trend in Scotland moved away from the construction of larger castles towards the use of smaller tower houses. The tower house style would also be adopted in the north of England and Ireland in later years. In North Wales Edward I built a sequence of militarily powerful castles after the destruction of the last Welsh polities in the 1270s. By the 14th century castles were combining defences with luxurious, sophisticated living arrangements and heavily landscaped gardens and parks.