this series has its similarities with the world of harry potter...this world is full of magicians as well..
the book presents an alternate world of London... it tells that magic has been part of society since the beginning and made some prominent people of history as magicians as well (Prague, Solomon, the Roman Empire, William Ewart Gladstone, Benjamin Disraeli)...
the magicians use their power to enslave demons... the more demons in your employ and the more powerful they are connotes a higher status in society... they use demons for their daily life routines... there will be a lot of pentagrams, magic spells and "demon calling rules"... in case you make any mistake in summoning or you slip out of the pentagram --> you're dead....
Bartimaeus is as djinni... or genie as we commonly used in the movies... he is a demon of mid level power...
here are the summaries of the books as per WIKI...
The Amulet of Samarkand
The first book in the series, published 2003, introduces Nathaniel as the gifted 12-year old apprentice of a middle-aged mid-level magician, Arthur Underwood. He assumes a magician name—John Mandrake—to protect him from rivals who would wish to harm him. When the magician Simon Lovelace cruelly humiliates Nathaniel in public, Nathaniel decides to take revenge by stealing Lovelace's most powerful possession, the Amulet of Samarkand. Unknown to his tutor, he begins the study of advanced magic in order to summon the djinni Bartimaeus and enslave him. Bartimaeus later overhears Nathaniel's birth-name, which greatly reduces Nathaniel's control over him, because demons can then cast counterspells. Things soon get out of hand and Bartimaeus and Nathaniel find themselves caught in the middle of magical espionage, murder, blackmail, and revolt. Together, the two of them defeat Lovelace's most powerful demon, Ramuthra, and Lovelace himself.
The Golems Eye
Published in 2004, the second book picks up two years and eight months later and features Nathaniel as a junior magician working his way up the government ranks. In this book Kitty Jones is introduced as an important character. She is a part of the Resistance movement which seeks to end the oppressive rule of the magicians. Nathaniel is tasked by his superiors to crush the Resistance and capture the members. His task is complicated when a seemingly invulnerable clay golem starts to make random attacks on London. Much to the displeasure of Bartimaeus, Nathaniel recalls the djinni to aid him in uncovering the origins of the golem, and to save his own skin.
Ptolemy's Gate
In the final book of the series, published 2005, Nathaniel is a senior magician and a member of the ruling council, an elite class of magicians in the government. Bartimaeus is still trapped on Earth by Nathaniel and is treated with disdain. Meanwhile, Kitty Jones has been hiding undercover and completing her research on magic and spirits. She hopes that this will enable her to break the endless cycles of conflicts between djinn and humans. The main plot of this story is a conspiracy to overthrow the government which causes the most dangerous threat in the history of magic. Together, Nathaniel, Bartimaeus and Kitty try to save the city of London from this dangerous threat.
Bartimaeus reveals to the reader the presence of an endless cycle wherein magicians summon spirits, magicians rule over commoners, spirits spread magic throughout a city, some of the commoners gain a resistance to magic, the commoners rebel against the magicians, the magicians are overthrown, and the spirits return to the Other Place until another magical empire rises to power. This cycle proves to be the main plot, which culminates in the overthrowing of London. Bartimaeus makes references to other magical empires, such as Baghdad and Egypt, all of which have fallen from power as well.
its a fun and entertaining read...