Free Writing Prospectus

Filed Pursuant to Rule 433

Registration No. 333-169119

May 23, 2011

* The investor fee is equal to the Yearly Fee times the principal amount of your securities times the index factor, calculated on a daily basis in the following manner: The investor fee on the inception date will equal zero. On each subsequent calendar day until maturity or early redemption, the investor fee will increase by an amount equal to the Yearly Fee times the principal amount of your securities times the index factor on that day (or, if such day is not a trading day, the index factor on the immediately preceding trading day) divided by 365. The index factor on any given day will be equal to the closing value of the index on that day divided by the initial index level. The initial index level is the closing value of the index on the inception date of the securities.

iPath Exchange Traded Notes

® ®

iPath S&P GSCI Total Return Index ETN

iPath Exchange Traded Notes (ETNs) are senior, unsubordinated, unsecured debt securities issued by Barclays Bank PLC delivering exposure to the returns of a market or strategy with the trading flexibility of a listed security. Investors can trade on an exchange at market price or receive a cash payment at the scheduled maturity or through early redemption¹, based on the performance of the index less investor fees. The iPath® S&P GSCI® Total Return Index ETN is designed to provide investors with cost-effective exposure to broad-based commodities as measured by the S&P GSCI® Total Return Index (the “Index”).

NOTE DETAILS

Ticker GSP

Intraday indicative value ticker GSP.IV

Bloomberg index ticker SPGSCITR

CUSIP 06738C794

Primary exchange NYSE Arca

Yearly fee 0.75%

Inception date 06/06/06

Maturity date 06/12/36

Index S&P GSCI ® Total Return

ISSUER DETAILS

Barclays Bank PLC long-term, unsecured obligations*

S&P rating AA-

Moody’s rating Aa3

The iPath ETNs are not rated, but are backed by the credit of Barclays Bank PLC. The iPath ETNs rely on the rating of their issuer, Barclays Bank PLC.

* We have not obtained a rating from any rating organization with respect to the iPath ETNs. A security rating is not a recommendation to buy, sell or hold securities, and each rating should be evaluated independently of any other rating. A security rating is subject to revision or withdrawal at any time by the assigning rating organization, and there is no assurance that any security rating will remain in effect for any given period of time or that it will not be lowered, suspended or withdrawn entirely by the applicable rating agency. Any such lowering, suspension or withdrawal of any rating may have an adverse effect on the market price or marketability of the iPath ETNs.

INDEX COMMODITY GROUPS

Energy 68.98%

Agriculture 16.04%

Industrial Metals 7.55%

Livestock 4.43%

Precious Metals 3.00%

Source: S&P as of 03/31/11. Subject to change.

INDEX CORRELATIONS

S&P GSCI® Total Return Index 1.00

Dow Jones-UBS Commodity Index Total ReturnSM 0.92

S&P GSCI® Crude Oil Total Return Index 0.96

S&P 500 Index 0.53

Barclays Capital U.S. Aggregate Bond Index -0.03

MSCI EAFE Index 0.60

Sources: S&P, UBS Securities LLC, Dow Jones Indexes, Barclays Capital, MSCI Inc., Bloomberg, BlackRock 03/06—03/11, based on monthly returns.

INDEX TOTAL RETURNS & STANDARD DEVIATION

(as of 3/31/11)

1-YEAR RETURN % 3-YEAR RETURN % 5-YEAR RETURN % STANDARD DEVIATION

ANNUALIZED ANNUALIZED% ANNUALIZED*

S&P GSCI® Total Return Index 22.73 -12.41 -3.34 27.31

Dow Jones-UBS Commodity Index Total ReturnSM 28.49 -5.20 2.57 20.76

S&P GSCI® Crude Oil Total Return Index 5.60 -21.43 -9.27 35.91

S&P 500 Index 15.65 2.35 2.62 17.87

Barclays Capital U.S. Aggregate Bond Index 5.12 5.30 6.03 3.59

MSCI EAFE Index 10.42 -3.01 1.30 21.44

* Based on monthly returns for 03/06—03/11.

Sources: S&P, UBS Securities LLC, Dow Jones Indexes, Barclays Capital, MSCI Inc., Bloomberg, BlackRock.

Index returns are for illustrative purposes only and do not represent actual iPath ETN performance. Index performance returns do not reflect any management fees, transaction costs or expenses. Indexes are unmanaged and one cannot invest directly in an index. Past performance does not guarantee future results. ForFor For current Index and iPath ETN performance, go to www.iPathETN.com.

¹ Investors may redeem at least 50,000 units of the iPath® S&P GSCI® Total Return Index ETN on a daily basis directly to the issuer, Barclays Bank PLC, subject to the procedures described in the relevant prospectus.

iPath® S&P GSCI® Total Return Index ETN

The S&P GSCI® Total Return Index reflects the total returns that are potentially available through an unleveraged investment in the

contracts comprising the S&P GSCI® Index, plus the Treasury bill rate of interest that could be earned on funds committed to the

trading of the underlying contracts. The Index is a production-weighted index of the prices of a diversified basket of 24 futures

contracts on physical commodities traded on trading facilities in major industrialized countries.

TOP TEN CONTRACTS INCLUDED IN THE S&P GSCI® TOTAL RETURN INDEX*

COMMODITY TICKER WEIGHTING TRADING FACILITY COMMODITY GROUP

Oil—WTI Crude Oil Contract CL 33.46% NYM Energy

Oil—Brent Crude Oil LCO 16.08% IPE Energy

Oil—Gasoil LGO 6.80% ICE Energy

Heating Oil HO 4.95% NYM Energy

Unleaded Gas ( ) RB 4.93% NYM Energy

Corn C 4.28% CBT Agriculture

Copper MCU 3.43% LME Industrial Metals

Wheat W 3.04% CBT Agriculture

Natural Gas NG 2.77% NYM Energy

Gold GC 2.46% NYM Precious Metals

* As of 03/31/11. Source: S&P, Goldman Sachs, NYM–NYMEX Division New York Mercantile Exchange, CBT–Chicago Board of T

rade, CME–Chicago Mercantile Exchange, LME–London Metal

Exchange, CMX–COMEX Division–New York Mercantile Exchange, ICE-ICE U.K., NYF-ICE Futures U.S.

An investment in iPath ETNs involves risks, including possible loss of principal. significant losses.

For a description of the main risks see “Risk Factors” in the applicable iPath ETNs typically have lower investor fees than currently existing mutual funds that invest in similar prospectus. markets and are available to retail investors. Buying and selling iPath ETNs will result in brokerage commissions.

Barclays Bank PLC has filed a registration statement (including a prospectus) with

The index components for iPath ETNs linked to commodities indexes are concentrated in the the SEC for the offering to which this communication relates. Before you invest, commodities sector. The market value of the Securities may be influenced by many unpredictable you should read the prospectus and other documents Barclays Bank PLC has filed factors, including, where applicable, highly volatile commodities prices, changes in supply and demand with the SEC for more complete information about the issuer and this offering. relationships; weather; agriculture; trade; pestilence; changes in interest rates; and monetary and other governmental policies, action and inaction. Index components that track the performance of a single You may get these documents for free by visiting www.iPathETN .com or EDGAR commodity, or index components concentrated in a single sector, are speculative and may typically on the SEC website at www.sec.gov. Alternatively, Barclays Bank PLC will arrange exhibit higher volatility. The current or “spot” prices of the underlying physical commodities may also for Barclays Capital Inc. to send you the prospectus if you request it by calling affect, in a volatile and inconsistent manner, the prices of futures contracts in respect of the relevant toll-free 1-877-764-7284, or you may request a copy from any other dealer commodity. These factors may affect the value of the index and the value of your Securities in varying participating in the offering. ways.

“S&P GSCI® “, “S&P GSCI® Index”, “S&P GSCI® Total Return Index”, “S&P GSCI® Commodity Index” BlackRock Fund Distribution Company assists in the promotion of the iPath ETNs. and “S&P GSCI® Crude Oil Total Return Index” are trademarks of Standard & Poor’s Financial Services iPath ETNs (the “Securities”) are unsecured obligations of Barclays Bank PLC and are not secured

LLC (“S&P”) and have been licensed for use by Barclays Bank PLC. The Securities are not sponsored, debt. The Securities are riskier than ordinary unsecured debt securities and have no principal endorsed, sold or promoted by S&P. S&P does not make any

representation or warranty, express or protection. Risks of investing in the Securities include limited portfolio diversification, trade price implied, to the owners of the Securities or any member of the public regarding the advisability of fluctuations, uncertain principal repayment, and illiquidity. Investing in the Securities is not equivalent to ® investing in securities generally or in the Securities particularly or the ability of the S&P GSCI to track direct investment in index or index components. The investor fee will reduce the amount of your return general stock market performance. at maturity or on redemption, and as a result you may receive less than the principal amount of your ©2011 Barclays Bank PLC. All rights reserved. iPath, iPath ETNs and the iPath logo are registered I0311 investment at maturity or upon redemption of your Securities even if the value of the relevant index has trademarks of Barclays Bank PLC. All other trademarks, servicemarks or registered trademarks are the—increased or decreased (as may be applicable to the particular series of Securities). An investment in property, and used with the permission, of their respective owners. iP-0364-0511 GSP iPath ETNs may not be suitable for all investors. iP— The Securities may be sold throughout the day on the exchange through any brokerage account. There Not FDIC Insured • No Bank Guarantee • May Lose Value are restrictions on the minimum number of Securities you may redeem directly with the issuer as specified in the applicable prospectus. Commissions may apply and there are tax consequences in the event of sale, redemption or maturity of Securities. Sales in the secondary market may result in

An investment in iPath ETNs involves risks, including possible loss of principal. significant losses.

For a description of the main risks see “Risk Factors” in the applicable iPath ETNs typically have lower investor fees than currently existing mutual funds that invest in similar prospectus. markets and are available to retail investors. Buying and selling iPath ETNs will result in brokerage commissions.

Barclays Bank PLC has filed a registration statement (including a prospectus) with

The index components for iPath ETNs linked to commodities indexes are concentrated in the the SEC for the offering to which this communication relates. Before you invest, commodities sector. The market value of the Securities may be influenced by many unpredictable you should read the prospectus and other documents Barclays Bank PLC has filed factors, including, where applicable, highly volatile commodities prices, changes in supply and demand with the SEC for more complete information about the issuer and this offering. relationships; weather; agriculture; trade; pestilence; changes in interest rates; and monetary and other governmental policies, action and inaction. Index components that track the performance of a single You may get these documents for free by visiting www.iPathETN .com or EDGAR commodity, or index components concentrated in a single sector, are speculative and may typically on the SEC website at www.sec.gov. Alternatively, Barclays Bank PLC will arrange exhibit higher volatility. The current or “spot” prices of the underlying physical commodities may also for Barclays Capital Inc. to send you the prospectus if you request it by calling affect, in a volatile and inconsistent manner, the prices of futures contracts in respect of the relevant toll-free 1-877-764-7284, or you may request a copy from any other dealer commodity.

These factors may affect the value of the index and the value of your Securities in varying participating in the offering. ways.

“S&P GSCI® “, “S&P GSCI® Index”, “S&P GSCI® Total Return Index”, “S&P GSCI® Commodity Index” BlackRock Fund Distribution Company assists in the promotion of the iPath ETNs. and “S&P GSCI® Crude Oil Total Return Index” are trademarks of Standard & Poor’s Financial Services iPath ETNs (the “Securities”) are unsecured obligations of Barclays Bank PLC and are not secured

LLC (“S&P”) and have been licensed for use by Barclays Bank PLC. The Securities are not sponsored, debt. The Securities are riskier than ordinary unsecured debt securities and have no principal endorsed, sold or promoted by S&P. S&P does not make any representation or warranty, express or protection. Risks of investing in the Securities include limited portfolio diversification, trade price implied, to the owners of the Securities or any member of the public regarding the advisability of fluctuations, uncertain principal repayment, and illiquidity. Investing in the Securities is not equivalent to ® investing in securities generally or in the Securities particularly or the ability of the S&P GSCI to track direct investment in index or index components. The investor fee will reduce the amount of your return general stock market performance. at maturity or on redemption, and as a result you may receive less than the principal amount of your ©2011 Barclays Bank PLC. All rights reserved. iPath, iPath ETNs and the iPath logo are registered I0311 investment at maturity or upon redemption of your Securities even if the value of the relevant index has trademarks of Barclays Bank PLC. All other trademarks, servicemarks or registered trademarks are the—increased or decreased (as may be applicable to the particular series of Securities). An investment in property, and used with the permission, of their respective owners. iP-0364-0511 GSP iPath ETNs may not be suitable for all investors. iP— The Securities may be sold throughout the day on the exchange through any brokerage account. There Not FDIC Insured • No Bank Guarantee • May Lose Value are restrictions on the minimum number of Securities you may redeem directly with the issuer as specified in the applicable prospectus. Commissions may apply and there are tax consequences in the event of sale, redemption or maturity of Securities. Sales in the secondary market may result in