Introduction: The Hanuman Chalisa is a devotional hymn to the Hindu god Hanuman, and takes its name because it has 40 verses (Hindi "Chalis" = "forty"). Devotional singing is one of the most common Hindu religious practices, and can be done either as an act of individual piety, or as a congregational exercise. Singing is also something that can be done by poor people, who have nothing more than their devotion to offer, or by illiterate people, who commit the songs to memory by hearing them.  The Hanuman Chalisa is one of the most popular texts, in no small part because it is believed to confer all sorts of benefits on those who recite it-benefits named in the text itself, which include health, general protection, and spiritual attainments. Like most Hindu devotional texts, the Hanuman Chalisa is based in the theology of the Name of God, which is seen as bestowing grace on those who speak it. Hanuman is one of the most popular deities in the Hindu pantheon, beloved for his strength, protective powers, and accessibility. The Hindu tradition portrays Hanuman himself as unceasing in his devotion to Rama, and this devotion not only makes him a model devotee for human beings, but gives him an intermediary status that makes him easier to approach than the awesome and majestic Rama, the divine sovereign. 

The Hanuman Chalisa opens with an invocation by the poet-saint Tulsidas (1532-1623). Tulsidas was an ardent devotee of Rama (and by extension, of Rama's servant Hanuman), and is also the author of the Ramcharitmanasa, one of the most popular vernacular versions of the Sanskrit Ramayana. The Hanuman Chalisa's final verse names Tulsidas as the author; this may refer to a different Tulsidas, since the oldest manuscripts for the Hanuman Chalisa do not appear until well after the original Tulsidas’s death (For this bit of information, I am indebted to a private communication from Prof. Philop Lutgendorf, at the University of Iowa). For millions of ordinary people, however, "Tulsidas" is the author of this text, and the text's devotional sentiments are completely consistent with those of Tulsidas. 

Opening Invocation

Purifying my mind's mirror
with dust from my guru's lotus feet,
I will recount Rama's spotless fame, which confers life's four ends.

I lack intelligence and understanding and so invoke the Son of the Wind, 

Give me strength, intelligence, and wisdom,
Take away my faults and shortcomings. 

Notes to the Opening Invocation: This verse deploys common devotional images, particularly the image of the guru's feet as a source of inspiration and enlightenment. One of the most common gestures of respect in India is to touch a person's feet (to "take the dust"), and then put one hands to one's head (or touch one's head to another's feet, which is even more respectful). Here Tulsidas describes himself as using his memory of his guru to purify his mind, and thus enable him to tell the story of Hamuman well.  The "four ends" are the four classic goals of life: wealth and power (artha), enjoyment (kama), religious duty (dharma) and final liberation of the soul (moksha).  "Son of the Wind" is one Hanuman’s names, given because his father was the wind-god Pavana. Indian mythology has a surfeit of epithets for deities and other heroic figures, but in translating this song I have largely subsumed these into a few more common names, since this will be less confusing to readers.  

Verses

1. Victory to Hanuman, the ocean of knowledge and virtues.

Hail! Lord of Monkeys, famous in the the three worlds!

The three worlds (a shorthand expression for "everywhere") are the underworld (visualized as like this world, except underground), the surface world, and the upper world. 

2.Rama's messenger, possessing immeasurable strength,
Anjana's son, named the Son of the Wind.  

Hanuman's fame stems from in his deeds in the Ramayana, where he serves as Rama's servant and messenger. Verses 9-18 allude to the most important of these.  The line’s second half names Hanuman's parents--his father the wind-god Pavana, his mother the celestial nymph Anjana.  

3. A great warrior, heroic, diamond-tough,
warding off the wicked, keeping company with the good,

4. Golden-faced, resplendent in fine cloth,
Earrings in his ears, and curly hair.

5. Hands resplendent with mace and banner,
wearing a sacred thread of munja grass.

Verses 4-5 describe Hanuman's physical appearance, perhaps to help the devotee create a mental picture.  Munja grass is used in rituals, including braiding into the sacred thread that all twice-born men wear after their adolescent religious initiation. The allusion to this sacred thread shows that despite his monkey appearance, Hanuman is a highborn being.

6. Shiva's son, and Kesari's delight,  

the whole world knows your brilliant power.

Hanuman is said to be to be a form of Shiva (and thus figuratively his "son"), who took birth as Hanuman so that he could serve Rama.  "Kesari" is another name for Hanuman's father Pavana, and thus "Kesari's delight" is another epithet for Hanuman.  

7. Wise, virtuous, exceedingly clever,
Ever intent on doing Rama's work, 

8. Delighting in hearing tales of Rama's deeds,
and dear to Rama, Lakshmana, and Sita.

Hanuman so loves hearing Rama's exploits that he appears in disguise whenever these stories are told. Of course, this gives devotees the sense that god is present with them.

9. In your subtle form you revealed yourself to Sita,
in your enormous form you burned Lanka,

This begins allusions to Hanuman's deeds in the Ramayana. After Sita was kidnapped by the demon-king Ravana, it was Hanuman who found her held captive in a forest grove.  He used his ability to change size at will to become small enough to sneak into the garden, where he reassured Sita that Rama was coming to rescue her.   He was captured and brought before Ravana, who decided to torture Hanuman by igniting oil-soaked rags tied to his tail. Hanuman first magically lengthened his tail to require immense quantities of rags and oil, then slipped from his bonds by becoming very small. He then reassumed a gigantic form and leaped through the city, setting it on fire.

10. In your horrific form, you slaughtered the demons, 
And completed Rama's work.  

During the battle for Lanka, Hanuman destroyed entire demon armies single-handedly.

11. You brought the life-giving herb to revive Lakshmana, 
and Rama hugged you tightly with delight.

This is Hanuman's single most heroic deed, and one of his most common portrayals.  Rama's brother Lakshmana had been gravely wounded, and could be saved only by a life-giving herb that grew on one Himalayan mountain.  Hanuman used his powers to fly to the mountain, but when he was unable to find the herb he carried the entire mountain back to Lanka.  This story highlights both his strength and his protective qualities. 

12.  Rama praised you exceedingly,
[saying ]
"you are as dear to me as my brother Bharata"!   

Rama's youngest brother Bharata faithfully served as Rama's regent while Rama was banished.  Many Ramayana characters are ideal types, and Bharata is the ideal younger brother—he is devoted to his elder brother (who as the oldest, will someday lead the joint family), serves his brother faithfully, and refuses to usurp his brother's rightful place.  

13.  Embracing cheek to cheek, Rama proclaimed
"The thousand-headed serpent will sing your praises"

 The figures mentioned in this and the following verses are all major or minor gods; Hanuman's deeds are so momentous that even the gods will sing his praises. 

14.  as will Sanaka, Brahma, and all the other sages,
Narada, Sarasvati, and the Serpent King.

15.  Yama, Kubera, and all the divine guardians."
What poet has the skill to describe this?

"What Poet?"  Tulsidas, of course! ("humble brag" here).

16.  You helped the monkey prince Sugriva,
Introduced him to Rama, and gave him a kingdom.

A magician's trickery estranged Hanuman's childhood friend Sugriva from his older brother Bali, who sought to kill him.  Sugriva and Hanuman were living as refugees in the hills when Hanuman met Rama and Lakshmana.  In exchange for Sugriva's promise to help search for Sita, Rama killed Bali and installed Sugriva on the throne (yes, it doesn't seem quite right, but to tell the truth the Ramayana story has some vexing moral problems).

17. Vibhishana kept your mantra in mind,
and became Lord of Lanka, as the whole world knows.

Ravana's youngest brother Vibhishana consistently condemned Sita's kidnapping, and urged Ravana to restore Sita to her husband. When Ravana threatened to kill Vibhishana the latter served Rama as a loyal ally, and became king of Lanka after Ravana's death.   

18.  Although the sun is a thousand light-years away,
You leaped at it in play, mistaking it for a sweet fruit.

The young Hanuman was perpetually hungry.  One day he mistook the rising sun for a red fruit, and when he leaped to swallow it the sun god threw him back to earth, breaking his jaw. In protest Hanuman's father Pavana ("wind") went on strike , and since in Indian physiology internal "winds" drive all bodily functions (digestion and elimination), the gods soon came begging for forgiveness. In recompense each god gave a boon to Hanuman, and these are the source of his strength and powers.

19.  Holding Rama's ring in your mouth,
You jumped the ocean to Lanka, this is no surprise.

Rama gave Hanuman his signet ring to prove that he was Rama's messenger. When Hanuman jumped the ocean to Lanka he put the ring in his mouth for safekeeping; the allusion here is also to the power of God's grace (represented by the ring), through which all tasks are possible.

20.  Any difficult task in this world,
Becomes easy through your grace.

21.  You are the gatekeeper at Rama's door,
None can enter without your permission.[1]   

This and the following verses stress Hanuman's protective capacities, and his role as an intermediary to Rama. Since Hanuman is also a devotee, he is seen as more easily approachable than Rama himself.  

22.  Your sheltering care brings all happiness,
With your protection, whom should one fear?  

23.  Your radiant power is collected to yourself,
The three worlds tremble at your battle cry.

24.  When your name is uttered, Great Hero, 
Ghosts and ghouls dare not come near.

25.  Ceaseless repetition of heroic Hanuman's Name
Destroys disease, and removes all afflictions.

In Hindu devotion the name of God carries power--to transform the person who repeats it and to bring that person closer to God, but also bestowing real benefits on the faithful, as mentioned here and in the following verses. 

26.  Hanuman releases from difficulties
Those who remember him in thoughts, words, and deeds.  

27.  All power belongs to Rama, king of ascetics,
but you are intent on doing his work.

28.  Whatever other desire anyone might have, 
that person gains reaps a blissful life.  

29.  Your fame spans the four cosmic ages,
Highest Perfected One, Enlightener of the world!

The "four cosmic ages" span a period of 4.32 million years, but are divided unequally. The earliest age is the longest (about 1.8 million years) and the best; the final age (in which we live) lasts "only" 432,000 years, and  is a time when righteousness and morality are almost completely lost.

30.  You protect true ascetics and the righteous, 
Destroyer of demons, and Rama's dear one.

31.  You bestow the eight powers and the nine treasures, 
Mother Sita gave this power as her boon.  

Aside from his protective powers, Hanuman can also bestow boons on devotees. Patanjali's Yoga Sutras name the eight powers (siddhi) as the ability to become very small, very large, or very light (and thus fly); to acquire what one wishes immediately, to make one's will irresistible, to control others, to create and destroy material things according to one's desire, and finally to suppress desire. The nine treasures (all gems) are pearl, ruby, lapis, diamond, coral, topaz, garnet, emerald, and sapphire.

32.  Always near when Rama's deeds are being told, 
you remain Rama's eternally faithful servant.

33.  Those who sing your praises find Rama, 
And forget countless lifetimes of sorrow.

Here (and in the succeeding verses) we find the image of coming to God through singing God’s Name, as well as reinforcing the image of Hanuman as an effective intermediary.

34.  When they die, they go to Rama's city,
Where it is said all Rama's devotees are born.

35.  Pay no attention to any other deities,
Serving Hanuman brings about all happiness.

36.  Whoever remembers heroic Hanuman
has difficulties cease, and afflictions destroyed.  

37.  Hail, Hail, Hail Hanuman, master of the senses!
Have pity on me, you are my spiritual master (gurudev).

38.  Whoever recites this hymn 100 times
Is released from bondage, and gains great happiness.

This and the following one show a standard feature of devotional texts—praise for the text itself, and describing the benefits of repeating it. 

39.  Whoever recites these 40 verses to Hanuman
Gains perfection, Shiva is the witness to this.

40.  Tulsidas is ever God's faithful servant,
O Lord, dwell in my heart.  

As noted above, this attribution to Tulsidas--the author of the Ramcaritmanas--seems unlikely. 

Closing Invocation

Son of the Wind, Remover of Difficulties, whose form is auspicious,

Dwell in my heart, King of the Gods, along with Rama, Lakshmana, and Sita.

This could be interpreted either as the writer speaking in his own voice, or a plea for grace from the devotee who has just recited the hymn.